Not a theory, just some thoughts and questions after watching "The Great Red Dragon":

Well, quite disappointing episode it was, wasn't it? 
Though Bertram now indeed seems to be the man (at least the head of TT), I'm still not so sure about him being Red John. IMHO, a few questions remain to be answered in the upcoming episode:

1. Why the hell are McAllister, Stiles and Haffner all three "burned to crisp" while not even being in the same place at the moment of the explosion? After all, Smith and Bertram are well alive - tough luck on McAllister being burned to ashes, despite standing right next to them at that very second...
Furthermore, I find it highly unlikely that Heller kills off two important characters such as Stiles and Haffner like that.

2. Why would Bertram want to kill Jane in his sleep, if he really was Red John? Sure, Jane at that moment is the only person besides Smith knowing about Bertram's tattoo...but still, as one can see, Smith is real quick at surrendering to the CBI when being threatened by TT. If he would have been caught after Jane's death, he still could've told everyone about Bertram's tattoo. Also: I don't think that Red John would simply cut Jane's throat in panic with Lisbon almost catching him in the act. For me, it doesn't fit the character in two ways - neither would Red John be that incautious, nor would he kill his arch enemy in such a dishononarable manner. (He could have done that every night for a few years now, knowing where Jane lives and sleeps ;))

3. Why didn't we get to see Partridge's face? I don't really think that he's alive anymore but it was a bit strange nonetheless.  

4. What is Bertram's list supposed to mean?

5. What's the big deal about that tea cup? "My favourite tea cup" - really? Doesn't it appear a bit off that Jane pretends to care all that much about a tea cup all of a sudden, despite being as close to Red John as never before? When he entered that room, he didn't seem to think about "letting go". After he was told what was happening and having his precious tea cup broken, he stopped, as if something struck his mind. Which leads me to the last question...

6. Why does Jane go to church in the last scene? He doesn't strike me as the typical religious guy at all, not believing in any kind of superficial or esoteric stuff. Is he waiting there for someone? Does he hope to find someone? Is he mourning his tea cup? I don't know.

As one can see, this episode somewhat asked more questions than it answered. If Red John really turns out to be Bertram in next week's episode, they better should deliver an awesome explanation for this and all the other remaining questions. The Mentalist and it's otherwise well-crafted Red John storyline deserve more than a plain "Yeah, whatever, bald guy did it all" in my eyes.

My guess after watching the 6x08 promo is McAllister, by the way. 

Greetings from Germany, stayed up all night to watch the latest episode :P

Sheriff McAllister is Red John just find out on wikipedia

I just compare some pictures of promo episode 8 and I was shocked, Red John is Sheriff McAllister. Until today, right now, I do not believe in this hypothesis, but now seeing ... has no other: Red John is Sheriff McAllister!!!

Hey I'm the guy of McAllister theory before episode 6x8 even began.
http://www.whoisredjohn.com/See-a-theory-Red-John/11543
I am staying with this theory, but something really interesting popped into my mind.

Let's call this theory "Resurrection"
It's funny that two of my prime suspects are now allegedly dead.
In my previous theory I stated that Bruno Heller had to show Red John in season 1, because he didn't know whether his show would get cancelled or not.  That's a fact, not one creator can predict that.

The two people of the suspect list that were shown are Brett Partridge and Thomas McAllister.

Brett was dead and Thomas was still alive. Episode 1x02 especially the Rock Paper Scissors game was actually the first game between Patrick and Red John.

But but but, I am doubting a little now. I still think it's him but now I'm doubting that Brett is still alive and that he could be Red John, let me explain why.

It's all about the body that was shown to us. The face wasn't shown, but it could be a simple explanation that Jack Plotnick isn't acting Brett anymore or he doesn't have time. My main thing was his left shoulder, it was knifed out. Why would someone do that?
This is the fun part: I think it could be a body that was used of a TygerTyger person as Brett Partridge's body. And that Red John removed that tattoo of the body. Remember Red John always uses a knife.
And my other concern was, why would a morgue guy tell Cho that the body of Partridge wouldn't be recognized anymore, it's too weird. He wasn't even buried in the ground. Every morgue keeps victims of a crime scene in a refrigerator, the reason for this is that everything stays intact for an investigation, this means also the face.
The writer of episode 7 'The great red dragon' told after the episode was shown to the public that we can expect a big twist again in episode 8.

I can tell you one thing and it will be a shown fact. One of my two suspects is going to be resurrected in episode 8 as Red John.

Sheriff Thomas McAllister "the owner of the vault where Bertram stole all the things under the name Thomas" Hence there was also wine what references to Napa county.

Brett Partridge "The ghoul" The definition of ghoul is a gravedigger. He is a forensic expert and an alleged Red John fan. As a narcissist you just have to love yourself.

Brett Partridge or Sheriff Thomas McAllister.

Our answer will come next week.

I was going with Sheriff from the start and I'm going to stick to it.

Out of everybody that presumably died, it's the Sheriff that would make the most sense to come back. Clearly, Smith and Bertram aren't RJ. Patrick wouldn't tell everybody the name, because he wants RJ for himself.

So, it has to be someone who is dead. I'm going to say McAllister actually makes the most sense, not only because he is my choice from the beggining, but there are a lot of other things that have already been explained.

The thing that caught my attention is the calmness when he is sitting. I don't know how to explain why he said that he isn't RJ when Patrick pointed the gun at him in the previous episode. But that was probably just a act, because he knew Patrick didn't expect to see 3 people with the tattoo.

What caught my attention from the start and especially in the Red Wedding episode was his incredibly good sense of smell. We can still remember the Strawberrys and Cream episode, where Timothy Carter, a.k.a. Fake Red John, told Patrick how his wife and daughter smelled before he killed them. Nobody has such a good sense of smell and that that was included wasn't a coincidence.

I still don't know how to connect him to Visualize. And I'm not sure how would he attract women, much younger than him, especially Lorelei, who is a hottie.

I am certain, more than ever, that it's Sheriff McAllister. The clues are right there for the taking. Adding on my theory here that it's McAllister: http://www.whoisredjohn.com/See-a-theory-Red-John/10471, here's why I'm ever so convinced after watching 6x07.

1. RJ is smart, he would've faked his own death in the bomb. He didn't bring the bomb to get rid of the other suspects, he brought the bomb in to write himself off the list. We all know RJ by now, he isn't stupid enough to get identified. We know RJ is part of the Blake Association. McAllister plants blood samples knowing it'll match positive to him and the team will pronounce him dead. NO ONE WILL LOOK FOR A DEAD MAN. And thus, ladies and gentlemen, RJ has successfully written himself off Jane's list. Whether Jane made it out alive or not, no one would still know of his identity. And now, while Jane blindly hunts for Bertram, McAllister is free as a bird to screw around with Jane one last time. Absolute Red John genius there. 

2. Bertram uses an alias in the vault - and it's Thomas. You can't get any more obvious a clue than that. BH and the writers are just throwing it in your face by now. 

3. The 6x08 promo. That man is not Bertram. It's Xander Berkeley aka Thomas McAllister. Go watch it for yourself.

4. The pigeon. It's in the promo. It's a symbol. A clue. The pigeon that Lisbon released scared off McAllister. He made it clear on the church rooftop that he hates pigeons. And now we see one in the promo. 

BH keeps to his word that RJ has been there from the start. RJ as Bertram is a disappointment. Yes, Bertram, as the head of Blake Association, makes all the sense in the world. But him, as RJ, does not cut it. There are still so much more lose ends to tie up before next week (the coded list, the dodgy FBI agent from Texas, why Partridge's left shoulder got skinned). We all know and love this show and there's always, always more than just what's been thrown at you. 

About 10 seconds into the 6.08 promo, the guy jumping through the window (presumably RJ) looks a lot like McAllister: http://i.imgur.com/IULSbGC.jpg