Hi Nick,

If you are flying on a oneworld carrier (and also on a ticket marketed by a oneworld airline), you are permitted to enter any oneworld airline lounge provided you are either/or:
- Travelling in Business or First Class
- oneworld Sapphire or Emerald status

There are a few exceptions. Therefore, whilst QR officially direct their passengers to the Air NZ lounge, you are still permitted to enter the Qantas lounges. You can hop between various lounges. I recommend you have a read through the oneworld lounge access policy and also search for various available lounges along with their individual rules through this link: https://www.oneworld.com/airport-lounges

Hope this helps.