Is Vy closer to Vbg with a variable pitch prop
Too long for a comment:

My POH does not show Vbg, only the 'normal' V's listed below, and even then only some of these are indicated on the Airspeed Indicator with the Green, Yellow, Red color bands. How would you determine Vbg? Experimentally?

VA,  Maneuvering Speed is the maximum speed at which you many use abrupt control travel.

VFE,  Maximum Flap Extension Speed is the highest speed permissible with wing flaps in a prescribed extended position.

VNO,  Maximum Structural Cruising Speed is the speed that should not be exceeded except in smooth air, then only with caution.

VNe,  Never Exceed Speed is the speed limit that may not be exceeded at any time.

VS,  Stalling Speed or the minimum steady flight speed at which the airplane is controllable.

VSO,  Stalling Speed or the minimum steady flight speed at which the airplane is controllable in the landing configuration at the most forward center of gravity.

VX,  Best Angle-of-Climb Speed is the speed which results in the greatest gain of altitude in a given horizontal distance.

VY,  Best Rate-of-Climb Speed is the speed which results in the greatest gain in a given time.