I know of quite a few cases of people getting "Original Routing Credit" when not flying QF, but instead being on eg AA/BA/CX etc and their route being stuffed around. It can go either way (and I think JohnK has some experience from his Finnair flying days of Finnair sorting it out), but I believe the easiest is to get Qantas to sort it out.
Now I don't know if the other airline has to approve the ORC, or Qantas just credits them and then charges the other airline, or the SC's/points come out of a mystery "customer care" pool etc. etc.
Going back to the original question - knowing more now about the cancellation and the new flight plans I would definitely follow it up with Qantas and provide the ticket information from the first ticket and the same from the second ticket.