what happened to bonjour?

It is available as a component of the main iTunes setup file which you can obtain from https://www.apple.com/itunes/download/.

tt2

Yes, but that version is 9 years old. The current iTunes installer carries v3.1.0.1 compiled in January of this year.

tt2

To be honest I'm not exactly clear if there is a distinction between Bonjour and Bonjour Print Services, however I'd be surprised if any current printer for Windows would require that you add a nine year old third party service to Windows to enable device discovery.

tt2

I've posted a discussion thread: https://discussions.apple.com/thread/250352614

Just can't seem to print from a Windows 10 laptop connected via Bonjour Print Service to my MacMini...

Would you happen to have any ideas?

You can download it from this website: https://support.apple.com/kb/DL999?locale=en_US

So if I re-install iTunes with the latest version, will this also include the latest version of Bonjour Print Service?