I checked the main page and you are right. The guest should support OGL 2.1.
But if I remember the trouble I have with host Windows 8 and Intel mobile chipset 4, the host driver from Intel does not support OGL 2.1 so I can't expect that the guest can really emulate it.
But this is only a wild guess that the host 3D adapter must be able to support OGL 2.1.
You have installed the VMware tools in the Windows 7 guest? Because you need the tools to be able to have Directx 9.0 and OpenGL 2.1 support.