SAQ Wine Ratings??
I know you asked for online resources...but if you don't have Michel Phaneuf's Guide des vins, you really should get a copy. I doubt you'll find more SAQ wines rated in one place, and based on what I've tasted I'd say he's pretty consistent and fair. The hitch is that it's an annual, so half way to being last year's news.
Nothing comprehensive. It helps if you read French. And, I hasten to add, listing here does not necessarily equal a recommendation on my part.
You can also check out the wine columns in Friday's La Presse and Le Devoir and Saturday's Gazette (the online Devoir and Gazoo columns are often locked to non-subscribers).
Here's a local English-language blog I like (though I couldn't disagree more with the blogger's assessment of Couly-Dutheil's 2005 Cherry Kool-Aid, er, Chinon rosé):
Also, keep checking this new Wine board. I and hopefully other locals will be posting tasting notes from time to time.