While it may be that the flight ex SYD operates mostly punctually, one potential difficulty is that if it is late into Bendigo, given fatigue management stipulations, the 0630 hours scheduled ex Bendigo to SYD next morning will be delayed (I am assuming that the flight crew who bring the evening one down stay in a motel - or the Shamrock - and next morning are rostered back to Sydney).
These sorts of delays occur with Qantaslink, Rex or
Virgin Australia Regional Airlines at 'outstation' airports like ABX, DBO and WGA to name a few, so logically (and unfortunately) at times they may affect the Bendigo to Sydney flight.
A typical example might be if SYD has a storm at say 1630 of an afternoon, and arriving aircraft are either held at waypoints, losing time, or in a worst case must divert as we've seen a couple of times in recent weeks. Then there's no aircraft to form the Bendigo-bound flight.