I've been looking into installing bspwm on OX X myself, and this was very helpful in figuring it out. However, it didn't actually work. The only way I found to get make to run properly was to copy the contents of /opt/X11/lib to /usr/include and copy the contents of /opt/X11/lib to /usr/local/lib. It's a dirty hack, but it got me through the make stage at least. I'm still configuring bspwm so I can't say for sure whether it works in the long run, but I figured I might as well put it out there.