No, it should not kill the liriope. GrassBGon is labeled to safely spray over liriope (they call it lilyturf, but they are referring to liriope). You may notice less vigorous growth after the treatment or possibly even a slight setback, but, if you carefully follow the directions, it should be generally safe. Some lawn chemicals actually do work better when applied more heavily than labeled; obviously this would not be a good time for that.

Thank you, Brandon! Actually, I wouldn't mind less vigorous growth! I think the bermuda and the liriope are in a race to see which take over the spot first.

I'll follow the directions to a "T"!

Is Grass B gone save to use in creeping phlox? Mine is being invaded by that devil, bermuda grass.

Dirtygardener,
Phlox isn't listed on the label (probably wasn't tested in their trials). Phlox is a dicot and GrassBGon targets monocots, so there's a good chance it wouldn't hurt. Test on a small area first and see what happens, if you want to be safe.