It amazes me how dormant, bench grafted vines muster up the energy, stored in their roots, to push through the mound of earth above them. It's a vineyard miracle :)
When the growth is about another inch long I will gently break down the mounds and let photosynthesis perform it's wondrous wizardry.
Of course this means the vines will need to be irrigated now as they will have almost depleted the moisture content of the soil they were planted in. Vinomaker, where are you?