If your employer has a presence in Australia, might be worth checking if they have a corporate membership. My former employer did, which gave employees globally access to the corporate rates/benefits (which included at the time waiving the joining fee). Otherwise I think you'd need to meet the joining requirements for a new firm outlined on the QF website.

You might be better off posing questions about the mechanics of joining Qantas Club on the QF board - expertise over this side of Flyertalk is probably limited to whether you can get into the BA lounge (and what champagne you'll get once you're in there ).