It's canon, and they seem like a cute couple. Up until I made it my goal to watch all the webisodes and films, I never paid much attention to them. I've achieved my goal for the most part--and watched a review of one of the two films I have yet to watch--so I'm all caught up now, and I'm glad that Gil eventually gained more confidence and finally told his parents where to stick it. Plus, it's clear how much he loves Lagoona and vice versa.

To me, it really does seem like they've grown as a couple over the course of the webisodes, which is a good thing. 

Conclusion: Yes.