Yes, once you create the line you can move it like any other object:
Code:
import viz
import vizshape
viz.go()
viz.clearcolor(viz.SLATE)
vizshape.addGrid()
viz.startLayer(viz.LINES)
viz.vertex(0,0,0)
viz.vertex(0,1,0)
line = viz.endLayer()
line.setPosition([2,0,7])
line.color(viz.RED)