Originally Posted by
LondonElite
Yes you can. People do it all the time. Most recently CX was giving away status to Amex Plat holders. Users would credit their flights to BA or AA, but use the CX card to get into the lounge. It's not a big deal.
People have reported that Aegean didn't like it when people did this. They were paying for benefits (for example when an Aegean *Gold used the lounge privilege when flying a *A partner airline in coach) but not being paid for miles by the operating carrier. I never had reason to want to try this, so I can't verify the exact rule in the T&C, but people here on FT claimed that this violated Aegean rules and they took it seriously.