I would if it comes off easily. The bark would absorb the stabilizing resin, which is ok if you are planning to include the bark portion in your turnings. If you plan to trim off the bark before or during turning, then it's a waste of resin. Also, I have learned that bark can darken the resin with tannins, which is not a really big deal, but it can darken the next wood you immerse in the resin.