The Qantas Club benefits webpage (
https://www.qantas.com/au/en/frequent-flyer/the-qantas-club/benefits.html) claims (emphasis mine)
So I think it's meant to be domestic only. Now as to whether this was "enhanced" at some point to remove international, or whether it was always like this and the stuff above was a happy error? Not sure.
Here's a picture I took at SYD International a few months ago
View attachment 303790
It mentions Premium Economy but not Qantas Club
But then again that sign doesn't have OW Ruby, and Rubys are supposed to be able to use Business check-in...