Thanks GenevaFlyer you are right. I checked the CX site and confirmed it too.
There are no lounges in Terminal G but I believe you can use a lounge in another terminal and then transfer across. Checking that out too.

I contacted AF and they say if I join their FF program I can use the lounge. Somehow I think there may be some restrictions to this so going to ask further questions.

When I did check the details of their programme it lists QF as a partner airline although AF is not listed on the QF site. I am also going to ask AF if QF is indeed a partner as I am a plat FF with them which would surely allow me lounge access.

I'm beginning to think I'm getting seriously paranoid about this. I'll think I'll let it go after I contact AF again.