Hello Valdo,
VrayColor2Bump doesn’t work with 3DSmax composite and VrayCompTex.
With vrayCompTex, it only use A and with composite, it only use base layer.
It only work with 3DSmax mix texture.
Sorry I have no time to show you sample or to make a simple test scene. I made heavy usage of vrayColor2Bump, this is very frustrating !
Hope you can fix it quickly ! 
Best regards…
vlado
2
I’m afraid you will have to make a scene. Works fine for me here.
Best regards,
Vlado
Hello Vlado,
Sorry, it was my mistake, I was forgetting that Addition in 3D and nuke is not the same as Addition in photoshop !
Next time I’ll try on a test scene before posting !!! Mea culpa, mea maxima culpa ! 
Best regards.
vlado
5
Heh ok, glad that it’s solved now 
Best regards,
Vlado