As someone wrote there is the ACP in Paddington with B&W and colour darkrooms for hire. $30 annual membership is reasonable plus the members card gets you discounts at a few labs & photo supply places.
ACP enlargers are pretty basic, if you want higher quality have a look at Blanco Negro at Alexandria http://www.blanconegro.com.au/front/darkroom.
I have also used Steve's darkroom at the Lighthouse at Bondi & he has a good setup.