Where file revisions are stored on OS X?
Versions are stored within the same file so a myfile.pages will have all there versions stored within it.

A version is only stored when you save from the file menu or use cmd- S

The version is just a bit of text that details the changes made since the last version so is not a copy of the file at that stage.

So if you sent the file to someone else they should get all the previous versions as well.