This is a
euonymus fortunei? If so, it's an invasive related to bittersweet vine. If it's an invasive, it's likely extremely vigorous and can be collected easily. Bittersweet is easy to dig, simply saw off the roots six inches out from the trunk, saw the trunk off three or four feet from the ground, plunk it in bonsai soil with 30 percent potting soil and it has no problem recovering.
Since it's a vine, turning it into a bonsai can present some issues, primarily with branching--vines don't "want" to make thick branches instead they want to climb. That's what wisteria, bittersweet and climbing hydrangea do. All of those however are made into bonsai.
Building branching will require allowing new shoots to grow wild and thicken near the trunk, while suppressing apically dominant growth...
