Arrive TBIT
QF11, 15, 25, 93, 107
Depart TBIT
QF12, 94, 108
Arrive T4
QF108
Depart T4
QF16, 26
Quite simple really. They used to have more flights operating out of T4, they were shifted across the TBIT after it was refurbished and the A380 started.
The only issue with the current set up is if you're arriving on QF108 from JFK and are connecting through to SYD (QF108) or MEL (QF94).