That’s what it appears to be. This is supported somewhat by the term “moonwise” not having a lot of historical usage, leading me to believe that it came along much later by someone who wanted a related antonym.

The only bit about the moon that seems to travel right to left are it’s phase changes, and even that is because we’re outside the rotation and watching along it’s horizontal plane. You’ll see the same thing with anything spinning clockwise in front of you: the closer edge goes right to left, the farther edge goes left to right.