Since you are trying to improve your wrestling via weights then adding mass wouldn't help after a certain point.
I guess I would start by deciding what weight class you want to be in.
If you can go up a class and still be competitive try to add muscle to your upper body.
*Before someone jumps my ass for ignoring legs let me finish.
Mainly you will want to be able to grab your opponent, pull him towards you, and then hold him to the ground for a pin or at least back points.
Try bringing up your dead lift which will help you pick up opponents. (Don't use straps)
Clean and snatch, if you have a good strength coach.
Barbell row! forget seated rows as they are not as functional here.
Wrist curls! for obvious reasons
train your neck too.
Oh and pull ups, pull ups, pull ups!
Some of the best wrestlers I have trained with looked like their back made up 50% of their total mass.