How does a Oneworld Sapphire rank in the seating decisions made by Qantas for their int'l flights? I recently flew QF11 and was surprised to get to SYD and have been taken out of my previously assigned seat (aisle seat upstairs).

After I selected a suitable seat, I asked the agent and she said Oneworld partners rank below any Qantas member in seat selection. Is that true? If so, would I be better off to put in my QF bronze number initially and then switch to my AA number at check-in?