Benefits are only for Primary Card Holder - Fine Print
Watch the fine Print. All the wonderful ‘benefits’ are for the primary card holder and they have to be on the same itinerary. I used a United card on which I am the primary card holder to purchase a ticket for a trip my wife was taking alone. I am the authorized user on what I thought was a joint account and she has a card with her own name on it. At the airport she was informed he had to pay the checked baggage fee and was not entitled to early boarding because the card was in my name and not I was not with her. When we called United card services about this we were told that we would each have to have our own separate card (and pay an extra annual fee) in order for both of us to get the flight benefits if we travel separately. Not worth it unless you use your own credit card and travel a lot on United.