Welcome to the forums, TheSophist!
These symptoms - the iPhone can see your Mac but can't actually sync with it - generally mean that the firewall on the Mac is letting OmniFocus send information, but is blocking incoming connections from the phone.
If you take a look at
this thread in the
Bonjour Sync forum, there are several tips which may help; if they don't, contact us via
email or phone (800.315.6664) and we're happy to provide further assistance!