Originally Posted by
Perche
On AA, one step up from economy is business class, or one notch below first class. On BA one step up from economy is not club world, it is just world traveler plus. I wasn't sure if BA considers a 50k AA mile redemption something that moves you up one notch from world traveler to world traveler plus, or up two classes of service to club world.
If you're traveling on BA and have BA miles (or AMEX points you can transfer to BA) the best option is usually to buy a discounted WT+ ticket from BA which you can upgrade to Club (aka Business) for miles with no co-pay.
You can't do that using AA miles on BA, just as holders of BA miles can't upgrade to AA Business from discounted coach tickets.
If your Wife is going to travel regularly and the upgrades are available on BA (they're hard to find at present), then additional cost of the WT+ seat isn't too much different from the cost of the AA co-pays and the mileage requirement is lower so that her purchased ticket will largely replace the miles burnt.
Overall the schemes are different but the end result is closer than it first appears.