No DJ can not interline your bags. You will have to drag them over to the international terminal. You may be lucky and find the DJ shuttle between terminals but others have reported it is usually nowhere to be found.

General recommendation: don't bother with DJ from BNE to SYD, always fly QF. The bags get checked all the way through and you get no-hassle transfers between terminals. Even better try to get on one of QF's international flights between BNE-SYD. Other than a fairly long walk right round the international terminal, this gets you the benefits on no domestic transfer at all, you can clear customs and immigration in BNE, and you typically get a much nicer flight on a 747 than regular domestic QF service. I check-in in the RCC at SYD when I do this. The only downside of getting QF to interline your bags is no *G Priority tags - if that applies - and we all know they have limited worth on UA anyway.