I noticed a JAL roundtrip that is somehow significantly cheaper when purchased through an AA codeshare (JFK-NRT-SIN, SIN-HND stopover NRT-JFK).

If purchased through AA, does this itinerary earn miles on Alaska at the JAL rate (good) or the AA rate (not so good)?

(I know *A earns based on the operating carrier, not marketing carrier. But not sure about this situation since Alaska is not even in oneworld.)

Also, is it just me or do JAL premium cabins earn in Alaska at really great rates (up to 225% in business and 350% in first?)

EDIT: Sorry I'm a bit new to posting...if this belongs in https://www.flyertalk.com/forum/information-desk-730/ I'd appreciate if a mod can move it there.