I have scheduled my boss to fly BA in a couple weeks (LAX-LHR, LHR-DUB with code share, DUB-LHR with code share, and then back LHR-LAX) and can't figure out the difference in miles she would earn by using a newly established BA reward program # or her main frequent flyer program, AA. Does anyone know how many more miles she will earn using BA than AA? (I do understand that she will have to pay money later to transfer the miles over to her AA account, but depending on the mileage difference, it may be worth it)

Also, once a reward program is selected, can you change it? I made the mistake of putting in AA but now may want to have the miles rewarded go into her BA account.

Thank you!