Yes. All Sonos speakers can be used in any country, provided you have the correct plug. They have power supplies in them that can handle any standard power source (110 to 230, if memory serves). So just a power plug adapter, or you can visit the Sonos shop (or third party stores) to get appropriate power cords, which just plug in to the speakers. 

I’ve used my Sonos devices in the US, India, and Thailand so far, with no issues. I honestly don’t recall what kind of plug is used in Australia, but if it’s the same as here in the US, no ‘adapter’ is even necessary. Seems more likely that you use EU style, but I don’t know. Either way, nothing to worry about.