I found the image on the right here. Many of the features in it match those in the postcard which places it as I thought at Petrie Bight. The photo on the right is from Picture Queensland, the State Library of Queensland, dated 1924. Here’s what the info about the picture says:
Wharves at Petrie Bight, Brisbane. The S.S. ‘Royal City’, 5411 gross tons and 3481 nett tons, docked at Nixon-Smiths wharves, Circular Quay, on 17 February, 1924. The S.S. ‘Royal City’ is discharging 19, 399 cases of kerosene, 20,000 cases of benzine and motor spirit and 650 tons of general cargo from New York and Port Arthur.
The 1924 picture has many additional buildings not in the postcard, so I’m sticking with my guess that the postcard is dated around 1910.
Unfortunately, I don’t think the ships in both pictures are the same. The stern of SS Royal City in the picture on the right is quite different from the stern of the vessel in the postcard.
Even so, it’s great to be able to more accurately date and place the postcard.