Codeshares to JNB/CPT
The AA RTW desk says that they are no longer allowed to book AA codeshare numbers on BA 54-59 (between LHR and JNB/CPT), even with AA TATL connections, but the online booking engine still permits you to book them. Obviously, this makes a big difference for mileage earning, -- these are long hauls, and elite bonuses can add up quickly. Interesting.