OWE on AA gets 3 x 23kg unless in business or first when it is 3 x 32kg.

However the BA website states that if your flight on a different airline has a BA flight number then you should get the BA allowance - 3 bags for WTP, 2 bags for Econ (both at 32kg). You should get the WTP allowance (unless you booked in the last few days).

So you should get 3x32kg but I think a discussion is quite possible!