You should not have a problem since you are on a QF flight number.
See this thread:
http://www.flyertalk.com/forum/qanta...hare-plat.html
And here on the Qantas web site: (
http://www.qantas.com.au/travel/airl...obal/en#qfclub)
Member Type: Gold
International Business Lounge
Next onward flight that day must be a Qantas or Jetstar Airlines+ flight number or a oneworld operated and marketed flight#.
One guest allowed and must be travelling with the member.