Yes, tannins by themselves mean nothing good or bad. I have eucalyptus that drop heavily into my pond and emit quite the tannins. Before I stocked the pond I even 'cooked' eucalyptus tea and made some nasty tea that was so dark you could barely see through an aquarium with it. Did a couple A & B tests with fish to see if they had any issue (yes, I went overboard). Results, actually had better growth & survival in a few month trial in the 'tannin tea'... now I don't take that as tannins are 'better', but I don't think they're by themselves bad.. as CJ said, it's the other water issues that are of concern pH, hardness, O2, etc.
Normally bg are the 'preferred' forage for a bass pond as they reproduce more prolifically than YP, OSS or PS. OSS & PS also don't grow as big, so your 22" bass will crop your brooders. Go catch some OSS and throw into that pond, and they'll end up being a snack. PS get bigger, but fill a smaller niche like RES and aren't a base for LMB forage. YP get the size, but aren't going to be a great 'base' for forage for your LMB since they're a predator in their own right.
I think your biggest issue is that it's a pretty big pond to stock by catching forage fish and moving into it. 1) you've got a base of big predators, so they'll eat anything small (TS, GS, etc), and 2) it's big so you need a decent about of forage that will avoid predation.
I'd find a hatchery and stock 800-1000 adult BG, or as many as you can realistically afford. If you can't do that, catching & moving may work but I hope you have more than one friend to help!
Regarding the cost of stockers. If anyone wants to build a 4 acre lake in my backyard, not fish it for years, and allow me to manage it, well, I'll happily stock the darn thing with some BG!
It sounds like you've feel into a great pond, just needs a bit of TLC.
p.s. - Pick up Lusk's book on raising trophy bass for a good read on how BG and bass are like ebony and ivory. Here's a quick primer:
http://www.bassresource.com/fish_biology/forage_bass.html
