I think it is Currently a limitation with Vray but just read on the Maya beta forum there was a featured added which solved it.
It’s something i’ve always wanted from Vray as i don’t like to work with multiple passes and shadow catching.
Well if you set the object to be a matte object and assign a reflective material then the reflection will be visible (unless you set Reflection to 0.0 in the vrayproperties of the object). I assume that “getting” visible is due to the environment beeing also reflected. How did you add the 2 HDRIs ? If via Domelight you can exclude the groundplane from the Domelight. If you got it in the environment slot you can add a VRaycolor map set to black to the environment slot of the ground material to override the global one.
I have put together an example that clearly shows the problem.
And the result needed at the end, Which for me so far has only been possible by Shadow Catching, ie applying white to everything and trying my best to only reflect the shadows on the ground, Then Comp it in post.
I’m not sure your images portray what the OP is asking. He wants the ground (which is matte) to be reflective and have its reflections show up in the render. Presumably without rendering in passes.
BTW killer portfolio you got there. Your quite talented.