As suggested I raised the issue with QF and got a response.
Essentially the wording of the rule is "In addition to Qantas Club lounges, you can relax in British Airways lounges (
Terraces and Executive Club lounges) and American Airlines® Admirals Club lounges...."
The lounges in Heathrow T5 are
Galleries lounges.
Looking at
http://www.britishairways.com/travel...ublic/en_gb#ui that doesn't leave much