Originally Posted by
Mozzarella
The issue is that when codeshare flights (AC flight number but TG, SQ, LH, NH or some other metal) are booked they show the AC fare class.
When its mapped to the other airlines fare, it maps to a non-earning or discounted fare class.
The problem is that the other airline's fare class is not ever visible (even in the fare rules) and as such you'll never know until you get to the airport to check into the codeshare flight (and you enquire at the transfer desk or at the gate).
In this case the OPs seem to mostly be talking about an AC W fare on TG. If that maps direct to TG W, it earns nothing (according to the AP chart). If it maps to TG V, it earns nothing either. If it doesn't earn points mapped straight over, it seems highly unlikely that it would earn points when mapped to another class.
I see AC Q on the HKG-BKK route using TG on some days. Then we would be talking about the issue in the thread you point out: If that AC Q maps to TG Q, it would earn points. If it maps to something else on TG, it might not. Then there would indeed be a concern -- fare class demotion due to non-transparent mapping is the issue being discussed in the long thread about operating carrier fare classes..