VFS is the virtual filesystem interface, it has been introduced by Sun with SunOS-3 in 1985. It describes the interface between a filesystem implementation and the rest of the kernel. The functions covered by VFS are e.g. open(), read() write() readdir().
FHS is a filesystem is a filesystem hierarchy standard and the filesystem hierarchy standard that is used by Linux that was derived from the FHS introduced by Sun for SunOS-4 in 1987.
In other words: VFS allows filesystems to be integrated into the driver structure while FHS just describes how to put files in the system directories.
In other words: there is no relation between both.