[Vwdiesel] Golf eating rear wheel bearings.

[H.Hagar]

Did you mean Bearing ?  ---not  bearings ?. (did you replace both inner and outer ?)

I have never seen a Golf  3     but they are likely tapered rollers.

Is it possible the axle is bent and it's 
causing the bearing to destruct prematurely?

Answer:  yes it is possible , but very unlikely.    To check the spindle is easy.

clamp threaded part in lathe or drillpress --and rotate. If it is bent the flange
will wobble.

One possibility is that you did not install the cups fully home and straight.

Hagar.