I would say that in zone 7, your need for trunk wrap on JM's is optional. Typically those recommendations are for colder zones that may experience big temperature swings in winter, where below freezing temps at night will freeze moisture under the bark but the sun can thaw it out rapidly during the day, resulting in splitting. In milder winter climates, the shift between daytime and nighttime temps in winter are not very wide and cold is less severe anyway, so much less of a concern.

I've grown and planted dozens of JM's in my zone 8 climate and never once wrapped the trunks for winter. And that includes all manner of colored bark cultivars as well as all my containerized trees. But zone 7 VA is not zone 8 PNW, so I will let those closer to you weigh in on this issue :-)

It certainly won't hurt. And can be helpful in deterring damage from deer and rabbits. Start at ground level and continue up the trunk until you encounter branching. I would avoid any fabric or paper wrap products as they can encourage rotting by holding moisture against the bark. Look instead for perforated plastic spirals as they are flexible and allow oxygen exchange and moisture wicking.