When I first got my male betta about 7 months ago, he was in the community tank with dalmation mollies, serpae tetras, playties and dwarf gourami. He was fine with everyone and no one bothered him but of course the dwarf gourami. That is why I ended up putting the betta in his own ten gal tank.
I think that if you do not have gouramis in your tank, and tiger barbs who can be fin nippers in their own right, you can probably add a betta to your community tank. I had a female in my community tank for awhile as well and she was fine. I was worried tho, about the distance of going up and down a tall tank for air, so I moved her as well to her own tank.
I think there is a lot of fish that bettas can be in with, but a female betta can be in with much more since she doesnt have those long fins to attract fin nippers. I do not think the angelfish and the bettas together are a good choice tho.

~ kate