Stan, I'm going to say... I don't know why not. Make sure the epoxy has been fully cured, and I'd probably double or triple the time that the packaging states for cure time.
Cured, they are both a skin of solid plastic, they won't dissolve into each other like subsequent coats of shellac would. Therefore, like you should do between coats of poly, I'd give a fine sanding to the epoxy surface to assure a mechanical bond can be formed between them.
And... before experimenting on a finished piece of artwork, I think I'd do the epoxy/WOP treatment on some scrap and see how it turns out. Just in case!