I don't see a pellicle in the photo. I think the big bubbles are from yeast, probably the Brett. What yeast strain did you use?
This should be okay to rack. This will give you a chance to test the SG and give the hydrometer tube a taste. It can take several months for the lacto to really sour the beer. IIRC, remove Berliner from the cake and leave Lambic on the cake. There are tons of threads on the Lambic and Wild Brewing forum.