What it says on the tin: I'm going to be flying SEA-OAK this weekend and it only just occurred to me that the AA/AS codeshare situation is wacky. So, the flight in question is marketed by AA. It is on AS metal. Both are BA partners...though the BA/AS chart doesn't list "J" (AA's Business) as a bucket. There's some difference in the earnings tables, too (it's not huge) but the biggie is whether or not I get tier points on BA (which in turn determines whether I can knock out BA status for the year). Does anyone know how this is likely to go?

Edit: And this is relevant mainly because if booking via AA gets me the TPs, it's definitely worth the $15 in fare difference to me. If not, it's not (and I'll probably fly on the slightly earlier DL flight instead).