Tamed a level 500 (max wild 600 custom stat affinities for wild/tamed dinos). Level 766 and Melee is at 1581%. Bite does either no topor or so little you can't see it before it goes away.

Breath only does approximately 1600 torpor vs. a level 180 Vanilla Bronto compared to the darts you can make from crafting the acid wyvern blood using syringes which does approximately 3600 torpor to the same dino with my 418.9% dmg rifle. Using a little math, you can figure out that the dart is doing abour 900 torpor with a standard 100% rifle.

The Bite attack should do torpor at least the same as the dart. The Breath is probably good where it is compared to vanilla dinos.