IVe gotten points when booking through Expedia; however, it seems the plane has to be MU operated. I flew a couple weeks ago from Thailand to China on what I booked as a MU flight. The flight ended up being run by Thai.

I got lounge access but no points and Thai Airlines never got my MU number when booking via Expedia (as MU always seems to get). So I guess MU flights operated by another airline don’t get SPG points even if booked as MU. Or maybe it does but thebautems were not integrated this time. I might have a flight to London soon on another MU booking that might be operated by another carrier - deciding whether to take that or Etihad.