Does this include Wildcards? They can use the team ability. Or does it mean characters that use the team ability, ex...nightwing.

You may choose a wild card team ability, but it only works for that team. If Bane Chooses SHIELD TA, he cannot get the bonus fighting against someone using the SHEILD TA via a wildcard TA.

If Bane chooses the Spider-Man TA, then he can target everyone with the Spider-Man TA for the bonus.

As far as Nightwing goes,

The word "possesses" is what matters. Yes, you can choose Outsiders and he would be able to be targeted by the bonus.

Thanks, I guess I was putting to much into it.

Sure he can. It says "use the chosen team ability", not "possess the chosen team ability".

I HAVE VOWED TO DESTROY YOU: At the beginning of the game, choose a team ability or keyword possessed by an opposing character. Modifying the attack value of Bane and adjacent friendly characters and the damage value of Bane by +1 when they attack opposing characters who can use the chosen team ability or has the chosen keyword.

Wildcards use TAs.

lol, that is very good to know. He just became a staple on my brute team

Didn't notice that.

But that seems a little strange that at the beginning they specify "possesses" then after they say "uses".

So what if I choose Batman TA, and Spider-Man isn't copying the Batman TA. Does bane still get the bonus?

If the character isn't using the TA, then you don't get the bonus.

I'm not sure about this.

DUAL MEMBERSHIP: Nightwing can use the Outsiders and Titans team abilities and possesses the Outsiders and Titans team symbols.

Nightwing can only use the team abilities, he doesn't possess them. Does possession of the symbols grant possession of the team abilities? The rulebook says:

When a character’s base includes a team symbol, it indicates the character possesses the team ability

Is possessing a symbol enough to possess (versus just use) the ability, or do you have to possess it on the base? If it isn't, then Nightwing can just use those two abilities and Bane can't pick them unless someone else on the team has them.

Possessing the symbol is good enough to possess the ability. At least that's what Stranger seems to think when he turns colossal. I would rule that Bane can pick up those abilities just fine. (But that's just me, and we french people are a strange lot)