Well, they're really young. The wire is already cuting in. You can leave it or remove it. If you leave it in, it will always show a spiral pattern on the bark. If you remove it, you'll have "wire marks for a few years, then they should go away as true bark develops.
JBP bonsai usually have powerful trunks. To get those trunks, most JBP bonsai are left to grow unimpeded for several years. However, there are things you can do to vastly improve the bonsai material you will have in, say, 5 years. Such as grow in a collendar, or collendar in collendar to develop nebari. Slant the tree so that it doesn't come up straight out of the soil. Things like that.
I would get the book "Pines" from Stone Lantern press. They have articles on how to grow JBP from seed. You can see how they do it, and try to match your trees to their program.
Meanwhile, get yourself some larger JBP stock to work with. These need to GROW for several years. More advanced material will allow you to learn JBP techniques. (Your trees are too young to do things like needle pulling, and decandling which really make JBP bonsai look finished.