Looks like it. I just downloaded it and checked, and all the install script seems to do is make a directory in /opt and copy the files there, and make a symlink.
So it's not really "installed" in the classical sense, so just deleting the folders should be fine-- though the whole thing is so tiny, don't quite know why you'd bother.
However, you might also want to drop Frank a note (the contact email is on the
Winetools page) to mention that there are no uninstall instructions in the archive or on the site, so it's confusing to new users like yourself.