I'd say if the grass is forming roots at nodes in contact with the soil, it's a good candidate for layering. The question will be if it will do this when separated from the mother plant. There's nothing to lose from trying it. You could just let it layer, and wait to separate it until it has fully formed roots, much as one would do with Hydrangea.

Zebra grass can revert to species Miscanthus, like almost any variegated cultivar. I'd probably remove any all-green blades.