if i play the infiltration BFC and i have someone with the batman ally, do they still benefit from the BFC? and what if i have a wildcard on the team as well may i have them copy the batman ally and benefit too?

That is the actual text.

Batman Allies can use stealth, so yes they can benefit from Infiltration as could Serpent Society.

However, at the beginning of the game Wildcards are only wildcards. They can't copy another TA until an action is declared. So wildcards cannot benefit from infiltration based only on their TA.