IOS – AirPrint over VPN

Usually, Bonjour only works on the local network and only its extension Wide-Area-Bonjour works through VPNs. Did you configure your Computer to use that or did you setup your router to handle that? Also, which other resources appear for the others at work?

But anyway, you don´t have to have File Sharing "turned on" on your computer (which will then cause the broadcasting of your computer´s name over Bonjour) to access others, so just turn off the services you don´t want others to see and you should be good.

Usually the sidebar shows Network Devices which are announcing themselves and are recognized by the 'Bonjour'-Service. For that to happen the appropiate Ports have to be used, in case of the 'Bonjour'-Service that would be Ports 1900, 5350, 5432 and 5353 (see "Well known TCP and UDP ports used by Apple software products")

My first suggestion would be to check your VPN-Server if these ports are blocked, which would prohibit the Devices showing up in the sidebar.

If the Raspberry is an SMB-Share you can try the following steps:

1. Open System Preferences » Network
2. Click the network interface you use for the shares (that probably should be your WiFi Connection rather than the VPN-Connection. You have to try both eventually)
3. Click on the Advanced button at lower right
4. Click on WINS tab, and manually enter the workgroup name of the server
5. Click the '+' under the WINS Servers list
6. Enter the IP of the server
7. Click OK, Apply, etc.