I played the female wingman many a times with some friends when we used to go to the clubs. And a female wingman just takes the place of the girl in her group as the guy dances/shakes the sheets/whatever with his chosen. And I was usually played bait too. "Hey, I know this is really high schoolish and I feel so stupid playing 10th grade games, but I have never seen my guy friend over there act like this about someone he's just seen at a club. He really thinks you're cute, but he got all shy all of a sudden and I HATE to think that he's passing up an opportunity to meet someone great." Since I'm a girl, the other girl didn't think it was really a pick up or too sleazy. It usually came across as cute and it cleared the way for my friend to go over.
Once the girl was separated from her group, I just stayed with her group for a few minutes chatting about girl stuff while my guy friend did his magic. Only time when this blew up in my face was when a gay girl was with the group of girls I stayed with and she saw the ploy a ways off because it's all female wingmans then.