You are going to want to be careful if you are blending it with a standard beer. The dextrins and other non-fermentables (left by ordinary yeast) in the standard could be eaten slowly by the wild organisms present in the lambic, and create bottle bombs like you say. That is, unless the standard beer is pretty thin and doesn't have much of that stuff left (say a Final Gravity of less than 1.010)
I'm guessing that a wild brew should probably reach a specific gravity of at least 1.000 (if not lower) before bottling. I am aging my first one right now, so we'll see how that goes. However, I think most blending of lambics takes place after they have been aged for a while, and is usually a blend of more than one wild brews, not a wild and a standard.
I could be wrong, however.