Seems a bit long, I recently had two flights with TG between BKK and HKG and miles posted ~5 days after both flights.

There's a whole thread here with average times for miles to post, I don't know what the average time for TG from that thread is, but if 12 days is clearly above the average, I would maybe try a retro claim. Not sure if A3 have any restrictions on that, l know on some airlines you have to wait 30 days after the flight(s).