No, I didn't line the bag. I had read notes over at Rav that it doesn't stretch really. And, I didn't join the bottom using the grafting thing, I did a 3-needle bind off which makes the bottom less likely to stretch.
I also brought the handles down all the way to the bottom, inside the bag at the sides. I placed what you'd call running stitches in and out of the handle through the side of the bag, so it is attached to the bag all the way to the bottom along the side. That will also prevent stretching I think!
I don't intend to load it up with lots of stuff anyways!
Here is a photo showing how far down the handle goes...except
that I stitched it down inside the bag, of course!