Steaks are very out of fashion these days, after all there is no great skill in cooking a slap of meat. As a result steak is often something that turns up on the lunch time deals in pubs in the city. Usually the result is tough and tasteless, however one of the rare exceptions is the Exchange Hotel.
For full steaks try places like the Breakfast Creek Hotel in Albion or the Norman Hotel in Woolloongabba. Options in the city are less good, but Cha Cha Char in Eagle St Pier is where you go for something at the top price range (over $70)