Hi there,
Unfortunately, this is not really “doing that”.
It allows to store bookmarks in your owncloud, via a bookmarklet.
But your browser bookmarks are not concerned.
I was more looking for something like Xmarks -under decommissioning- (or Eversync that I installed meanwhile) : you naturally use your bookmarks within your browser (FF or anything else), and the Cloud is simply used as a repository to sync all your browser instances bookmark DBs. An add-on in the browser being used to keep this local DB synced with your central repository…
I hope we will have a solution someday, that will take benefice of OC bookmarks, while allowing embedded usage of browser bookmarks DB.