The more practise you get, the better! So if you have time & money to do course in Australia, why not!! I don't know what area you'll be staying, but we used to go practising near airport, there are a few long streets with no hardly any cars, so it was a good place to get comfortable with the bike, practising turning, etc..
For myself it took some time to get used to, especially because I am from Canada and everyone drives on the opposite side of the road! I have to say there are areas in Bali that are quite dangerous to drive, so in those cases I feel more comfortable getting taxi or someone else to drive me- better to be safe than sorry and know your limits!