Im in Sydney without a car and generally speaking the transport to the bluies is fine, takes 2hrs 15 mins to hit blackheath then its 20 min walk to the local crags...it leaves early enough from central to get into blackheath for around about 930...
I havent climbed in the city so far just because the effort it takes getting to a chossy sea cliff or boulder problem is better spent getting to the mountains!
Dont forget you can always take your mountain bike on the trains here and bike it to the crag...
Al
P.S. Feel free to PM me if you ever fancy a climb.