I will be traveling with a friend on United Airlines, but we are on different reservations. I am entitled to Premier Access (Star Alliance), but my friend is not. Can they use the Premier Access security, check-in, and boarding with me if I present a card or my boarding pass with my Premier Access? If this works, does it work for multiple people? Remember, my friend is traveling on United, on the same flight- we are just on different PNRs. Thanks!