How can I set up DNS for Bonjour and AirPrint to advertise printers across subnets
I have solved this problem by allowing a selected group of the guests to be on the same LAN as the printers; however blocking them significantly with firewalls so that only the printers and a few other machines needed, can be reached from that specific wi-fi network.

If you see that I have provided this answer to my own question;  I'd still love to hear how to configure DNS for Bonjour in the current versions of OSX and Server, and otherwise forward Airprint or other protocols as examples.