Ok, I've got a BW going right now. I started with straight lacto and I'll pitch the 3191 soon. I'll keep it around 70* and let it go for a while.
My question is this - Wyeast says it takes 3-6 months of aging to fully develop the flavor characteristics. Does this mean I need to leave it on the yeast that whole time or can I bottle when it's finished and let the aging take place in the bottle/keg?
You are safe to bottle as soon as the gravity is stable, assuming it is sub-1.005. It doesn't take much extra fermentation for Brett to over-carbonate a beer, and you'll probably be aiming for the high end of the scale anyway.
Check out The Mad Fermentationist for my adventures in fermentation (cheese, bread, ginger beer plant, and of course plenty of funky beer).