All good @Isaac Ct the bars on the side was a bit confusing as the only other type I could think of was a Onion Trevally which look similar to yours but have a spot on the gill plate, but they don’t come that far south, though by saying that one has just been recorded in the last couple of weeks down in Perth on the west coast which is a long way south of where it’s been previously recorded.
I recon @dirvin21 nailed it. 👍 ……. Till some one corrects us 😀
Certainly not a common capture in Sydney.