IME Qantas serves an all-day snack service on shorter P.M. flights (excluding a small dinner time window). There are 3 choices, usually; soup, salad and cheese-based-snack. On a late flight the cheese-based-snack is normally cheese & crackers, during the day it might be a toasted sandwich. QF do not serve a side salad with these meals, although the salad option itself is normally quite substantial IME.
Of course if the OP was still hungry after eating the J meal/snack on VA, there are many other things available for them to eat on Virgin; besides the pantry snacks, they could have asked for a sandwich or wrap off the economy BOB menu - for free!
One should simply let the CS know they are still hungry and see what might be offered. IMO this is yet another area where VA service really shines, as the CSM on QF is only able to offer still-hungry J customers a small packet of pretzel-nuts.