I also believe that Brett Partridge or someone else outside of law enforcement is Red John, but he does not work with or for the Tyger Tyger organization. I believe that Tyger Tyger is a multiorganization law enforcement task force that was originally formed to find Red John. That is why they are keeping track of Patrick. Most likely they should have disbanded a long time ago but probably expanded on their own for their own shady reasons. I'm not sure if they are even trying to capture Red John anymore or are just waiting for Patrick & Lisbon to get him so they can take credit, either they are up to their to their own no good. But I think Red John is also trying to keep track of them, that is why he said Tyger Tyger or the poem to both Patrick and Lisbon & when they didn't respond...neither died (and plus he seems to have a fondness/respect for them.) The added purpose is to turn them to the notion that Tyger Tyger exists. Once Red John is captured/killed then Patrick & Lisbon will focus on taking down Tyger Tyger...to keep the plotline going. Right now the organization doesn't know that Patrick & Lisbon know anything about Tyger Tyger which is why the three (Bertram, Smith & McAllister) asked what Patrick knew. They thought he was tracking down Tyger Tyger vice the ID of Red John. This is another reason why Red John uses outside people to get info from inside CBI.
An interesting side note, in the military, a Tiger team is a group formed from all groups for a particular task. Everybody typically keeps their normal jobs but add a responsibility to meet to work on the Tiger team task. I found that coincidental.
