Originally Posted by Stripe

I don't see any T&Cs online that would suggest that you must be an Aadvantage member (and have your Aadvantage number on the reservation) in order to receive and purchase instant upgrade offers. However it wouldn't surprise me if the AA software won't work without it.

I wonder if members of other OneWorld programs see the offers. One of the requirements is that the flight be AA marketed and operated, so if they bought a BA codeshare, for example, they wouldn't see it.