I'm confused about whether H9 Control running on a Mac is supposed to be able to link to the H9 pedal via Bluetooth ?  It doesnt work for me so far.  But there's no problem linking with my iPhone.

Yes, this should work fine for you.  A lot of people are using this feature.  The H9 Control manual has some instructions on connecting via Bluetooth on a Mac:

http://ftp.eventide.com/ljdl/www/H9ControlUG/H9ControlManual_ConnectingOnMacOSX.html#MacOSX_via_Bluetooth

Also, if you're running OS X 10.10 or higher you should make sure that you're using the build of H9 Control made for 10.10 or higher.