I vote for greasing not only the threads of the chainring bolt but also the flanges. The application of the grease on the flanges needs to be light though because if applied too heavily the squeezeout can attract a lot of road dirt and necessitate lots of extra cleaning.

Having a Pedro's micro grease gun with Rock-N-Roll Super Web Grease is awesome for this application. You can apply a tiny bit of the viscous grease right where you want it. Strangely, even when torquing chainring bolts regularly it is still possible that they might work themselves loose. I have come home from rides several times over the last few years and not noticed that where I should have 5 chainring bolts, I mysteriously now only have four.