Originally Posted by
jackal
AGR Insider can confirm, but I don't think so. The Club Acela agent usually asks for a boarding pass, but it's mostly so they can mark down with train you're in so they can call your train for boarding. I've used the PHL CA with a UC card several times when not taking Amtrak and the agents had no issue with me just saying "I'm taking SEPTA" (although they gave me a look like "what are you wasting your time in here for, then?").
Amtrak travel activity is not required in order to use the United Club card as an entry credential at ClubAcela. Note that the United Club card entitles the bearer and
two guests to ClubAcela entry. The two-guest allowance is unique to ClubAcela entry for United Club members.
United Club cards are only accepted at the ClubAcela-branded lounges (NYP, PHL, WAS, BOS). They are not accepted at other Amtrak lounges, including Metropolitan Lounges or first class waiting rooms in other cities.