I've just started to work with figs, and am trying to start some cuttings in several different ways to see what works best for me. I am trying some in potting mix, just dipping in rooting hormone, and sticking in a pot. Well at least one has some mold forming near the soil line. What to do? Q-tip dipped in bleach? Spray with dilute hydrogen peroxide? I put the pots in a plastic bag. Maybe not enough air circulation? If so then how to keep the humidity without mold? I open the bag daily but......

I had this happen with a cutting as well.  I tried everything from coating the cutting in wax, to bleach rinses, to hydrogen peroxide dips.  Nothing worked.  I finally took the cutting and buried it an inch deep in new soil mix and waited.  In time I saw roots, and a week or so later I got a shoot pop out of the mix.  

My guess was that since I only saw the mold above the soil line like you, that was the good environment for the mold.  So, I changed its environment.  I have no idea if it was causal or not, but for me it worked.

Since you already treated with H202, I would also try to regularly remove the bag (once a day or so) to let some fresh air in.. Also consider making an airhole or 2 in the bag just to allow some of the humidity to escape and a little more air exchange.. If this doesn't seem to help, I would definitely consider Visceral's advice with carefully changing out the current medium and starting fresh.. best of luck to you! Mold stinks, but it can be beaten so don't give up :)