The OOL/SYD flights are catching a lot of the regular Business flyers out now too... many, who are used to a free wine on their BNE/SYD sectors, are now having to cough-up cash for a wine on their flights OOL/SYD.
As others have indicated, sometimes on my flights between CNS/BNE and OOL/SYD I'm given a free one with a wink or "change" due to status or if the crew know me or if the CSM comes and does a welcome and asks if I'd like anything, ("a wine would be nice"... sometimes from J, other times just a "free" one from the cart). When I order a wine, I do try to take the perspective not to be too disappointed when asked for the money, as technically I am getting what I paid for and as advertised, and to take it as a bonus if I do get a free one, but it'd be nice if Qantas could drop the charge altogether. It would be another positive differentiation from the competition.
It's probably also worth noting that you can tell some of the staff find it just as frustrating having to enforce the different rules. I'm sure they are just as tired having to explain when and why you pay on this flight/time/sector versus another. Though, like boris indicates, it'd be disappointing/frustrating when they get it wrong.