No it's not okay to offer upvotes as prizes. That goes against what the Pokebase is for and basically means bad posts could be given many upvotes.
However, we do have the option to give bonus points, which I would be fine with. Anybody who wins a Pokemon tournament is obviously good at Pokemon and so would deserve more points here. I would say not more than 100 (for first) per tournament. Maybe 1st=100, 2nd=50, 3rd=20.
I will check if I can set mods to give bonus points. Otherwise just let me know when you are done and I can dish out the points.