Would more ram increase the vram/performance for playing games with the Intel HD 4000?

Intel HD Graphics 4000

Apple Computers using the Intel HD Graphics 4000 as the primary or secondary GPU reserve 384 MB to 1024 MB of system memory.

Products with Intel HD Graphics 4000 include:

• MacBook Pro (13-inch, Mid 2012)
• MacBook Pro (Retina, 13-inch, Early, 2013)
• MacBook Pro (Retina, 13-inch, Late 2012)
• MacBook Pro (15-inch, Mid 2012)
• MacBook Pro (Retina, 15-inch, Early, 2013)
• MacBook Pro (Retina, Mid 2012)
• MacBook Air (13-inch, Mid 2012)
• MacBook Air (11-inch, Mid 2012)
• Mac Mini (Late 2012)

I'm not sure what you are asking. Adding more physical RAM enables the GPU to share more of the RAM with the GPU - think of that as more VRAM. This will help speed up certain GPU intensive activities that require VRAM. As for adding more RAM to the computer:

Adding RAM only makes it possible to run more programs concurrently. It doesn't speed up the computer nor make games run faster. What it can do is prevent the system from having to use disk-based VM when it runs out of RAM because you are trying to run too many applications concurrently or using applications that are extremely RAM dependent. It will improve the performance of applications that run mostly in RAM or when loading programs.

The integrated GPU uses shared RAM. The maximum amount is determined by the amount of RAM installed. Going from 8 GBs to 16 GBs will add an additional 128 MBs of VRAM. The maximum amount is 728 MBs. The maximum amount of physical RAM is 16 GBs, not 32 GBs.

More Ram does not = Faster Speeds. It allows for more apps to run simultaneously.

Yes, that is correct.