There are two different policies at play here:

1. BA's HBO fares;
2. AA's domestic US baggage policy which is (and has been for the past few years) = 0.

The latter contains waivers for various and sundry categories -- all set forth clearly on the AA website -- for F, its own elites and OW. Domestic US bag fees, however, are pretty minor, so this isn't really a huge issue.