OP if you are worried - I'm sure that QF will move you to the earlier SYD-BNE (which will likely be no more than an hour earlier) and then you will have plenty of time. (Or if there is another option which suits you - ask for that).
FWIW - If I were on my own, I'd do a 40 minute connection at BNE ... but I wouldn't if I were with some of my relatives who get a bit worried about these kind of things.