Well, if you wanted you could have preferred seating on AC flights, but this is not really something you should seek on its narrow body fleet as the first three rows of the back cabin offer less pitch than the balance of them further back. STARGold could get you an op upgrade from time-to-time, as long as there are no AC SEs or Elites in the cue. But not much more than the usual benefits of lounge access, priority bags and check-in, extra checked luggage allowance.
However, if you are on an H fare, as you post, then you could be upgraded by an AC Elite or SE who is upgrading and has a couple of extre SWUs. How you seek out such a kind soul is anybody's guess, but you could post flights and dates here and maybe win the Aerolotto!