I could be wrong, but I thought Bret forms a pellicle when acting is the presence of oxygen. Depending on what you using for primary you may get one, or not. Plastic buckets have a large amount of 02 transfer, even more than a barrel, so if your primary is plastic you may get one. If you're in glass with an airlock, you may not.
As for how far down it will go, I wouldn't be surprised if it doesn't make down to 1.010 given how high your OG was. Others will likely have more experience here, but I assume that some of what's left behind after the primary ferment of a beer this big is not only dextrans but unfermentable proteins or even longer chain sugars that the Bret won't be able chew through. Anyone with more experience in this regard? I'd love to know if Brett will really dry out something this big beyond the 81% attenuation he's already got.
Braufguss, looking at your sig, looks like you've got a lot more experience with this than I: have you seen 91% attenuation in a beer this big when finished with Brett? (That's what 1.010 would be if OG is 1.110.)
It's a pretty acid tolerant bug, however. I think it's still active late in lambic fermentation when the pH can be down in the 2-3 range (though pediococcus is playing a role at that point as well). In your case I doubt that's a major factor at this point.
Primary: wild yeast and dust motes
Primary:Premium Bitter 2
Secondary 1: Straight Lambic Solera
Secondary 2: Flanders Red
Bottled:JP BDG, Premium Bitter 1, Oatmeal Imperial Stout, Pearl-Beer Lambic, Chimay Grand Reserve Clones, Chocolate Imperial Stout, Adam Beer Attempt
On Deck: Elysian Avatar Clone