Remember that of you are connecting from an international flight on Australian Airlines to a Qantas domestic flight (QF400 or greater), then you will need to collect you bags at the international entry point and clear customs anyway. You then need to re-check them at the QF Domestic Checkin desk after clearing customs. So interlining is not all that relevant. Even if the bag is tagged to the findal QF destination, you still have to collect at the international arrival gateway and re-check after clearing customs.

If you connection is to the domestic sector of a QF international flight (QF399 or below) then the bag will be interlined between AO and QF for collection at the last point of travel on an international flight number (ie where you clear immigration and customs).

However, for connections to AO flights leaving Australia, interlining is relevant and is done by Qantas at the QF domestic checkin.