Yep, right so far!
At this point, your back is on. I lay the batting on the back, then I lock my horizontal (no channel locks on an A-1, so I just clamp the wheel), and run a straight line. This gives me a nice straight edge for the top edge of the quilt top. After I center the quilt top on that edge, I pin it, then run a 1/8"to 1/4" basting line, and pull the pins. I also baste the sides each time I advance. By basting the tops and sides, I have a nice square quilt, I don't have to watch out for pins and the binding goes on with no surprises.
Clear as mud?