I just noticed the mention of the Covenant Sinus Wodinis in Guardians of the Forests. It's on the southeastern coast of Norway, it's a Bjornaer covenant, and it's mentioned in Guardians on page 19. Now, for the question: is there any other information anywhere else about this covenant?
Perhaps Mythic Seas? I seem to remember a lone covenant mentioned there but can't get at my book to check. The other possibility would be in Land of Fire and Ice, again, no book at hand here.