This one's just not quite where you'd expect it. There's an Application Method called "Get VI Version". It takes a path and returns version info. It has to be an application method, because once you load the VI (required in order to get a VI Reference) it mutates to the version of LabVIEW in which it is being loaded, and the VI isn't in the old version anymore.
As an aside, using the class browser (CTRL-SHIFT-B) might have been helpful in finding such a property / method.
