AA lifetime plat, booked a BA flight on AA (2 out of a three legs on a multicity itn are on AA). I see the record locator for BA on the AA website, however, when i go to choose a seat on the BA flight, BA wants to charge me. I thought oneworld sapphire allowed me to choose seats for free.

Not the end of the world, ii am in business class (club europe) and only 1hour flight. Could it be that i am on a BA cityflyer flight?

thanks