It should, in theory drop the gravity, but how much is dependent on how much brett food was left in the beer when you added the roselare. Even though the brett can break down the more complex sugars, that regular sacc cannot, it cannot eat all forms of sugar. Assuming your beer went into the secondary at 1011, I would think you have some activity in there, but it may take time. Also, like sacc, brett has optimal ferment temps so it could just be that it is too cool for it to do its thing, or you need to wait a little more.
In short, your primary strain may have eatean more of the sugar than you thought it would, or you need to give it more time. I doubt it will get to 1.000.