I was hoping someone might be able to answer a question regarding booking on AA as a BA Silver. I am thinking of booking a flight with AA Advantage Miles, not Avios. I am a BA Silver and when I usually fly AA, I get to enjoy One World Sapphire benefits such as lounge access and priority security, etc., because I always use my BA account.

If I book a flight on AA using their AAdvantage miles, can I simply show my BA silver card to personnel at the check-in or Admirals Club to gain access, or will I be denied benefits because the booking was made using my AAdvantage account, with which I have no status?

(Something similar happened at Barajas in Spain when I bought a ticket to MUC using Iberia Avios, which I transferred over to Iberia from BA. To take advantage of the extra baggage allowance offered to OW Sapphires, I presented my BA Silver card. It took a lot of haggling on my part, and a call from the check-in counter employee to his supervisor, to finally get Iberia to give me the benefit since my Iberia membership number was on my ticket, not my BA number).