My wife and I have a flight on AA from RDU to LGW in a few weeks. We booked that itinerary as a last resort because the prices were so darn high for the dates we were looking for.

It will total around 7k miles. We both have BA accounts, but neither of us have AA. From what I remember, BA does not allow me to credit the AA miles to my BA account because it is a transatlantic flight, right?

If that is the case, what should I do? Should I just open a AA account for the miles, or should we open a different account with a oneworld airline (like Qantas or something) for the miles?

Thanks.
--Alex