You should prune a few months prior to going into your fall in Australia. You want to get some new growth started before the tree slows down for winter. Although your winter is unlike mine, they still slow with growth there.
Rick
"Many times a day I realize how much my own outer and inner life is built upon the labors of my fellow men, both living and dead, and how earnestly I must exert myself in order to give in return as much as I received"