My understanding is that TALT flights that are part of the joint venture have separate rules.

The elite lists are combined at status level with a preference then given to the operating carrier. So FB Plat and DL DM/PM are picked first with a preference to FB Plat and the higher fare class. Then FB Gold and DL GM. Then Silver.

This seems to be correct because I have a PE (S class) booking with AF in which my SM# indicates FB Plat.

My understanding is that intra-Europe (and thereby flights not governed by the JV) would be the reverse of Delta: All FB elites ahead of all Delta Medallions. That makes sense since FB elites are behind all Delta Medallions on Delta-operated domestic flights.

Does anyone know if FF#s indicate program origin? I'd assume that while I'm listed as a FB Plat, the AF agent could see that it is a Delta number.