Originally Posted by
Rubecula
Currently if you book a 2class flight on AA in domestic first >2000 miles you get 210 TPs if on AA flight number but only 140 TPs if on a BA codeshare. Who bears the additional cost, AA or BA?
The marketing airline buys the miles, so that would be BA.
In any event, BA R/I gets the same number of miles as AA F/P/A in BAEC (150% + tier bonus).
If you travel in BA J/C/D then you get 250% which is more than AA F. But BA swallow that because they get a bigger share of the revenue if you are on a BA marketed flight.
There is no cost for tier points.