Not an Aussie but have been to Sydney about 30 times.
A GREAT place. Sydney is a good fun town and taxis are cheap so get around. Don't waste space in your suitcase taking too much clothes. It's hot there. Dress code for daytime is boardshorts and tshirt plus flip flops.
The seafood is to die for. Do what Aus911 recommends, but if you can squeek it in, go to Watson's Bay and there is a seafood place there that sells maybe the best seafood you have ever eaten. And the beer is good too.
You will
enjoy Bondi.