To be honest, Bonjour for Windows hasn't actually done anything for me...
Bonjour is great in that you can chat with people on your network easily, you can connect two computers in a network and they immediately recognize each other, you don't need to configure your printer when you share it...
But none of that has truly worked for me in Windows. Sometimes Windows devices show up in my "Network" panel, sometimes I have to connect directly with their internal IP address. Printer sharing (Mac --> PC --> Printer) still hasn't worked predictably, so I just transfer the file and print from that computer...
In a nutshell, ultimately, everything will work, though it'll take more work and headache (though not necessarily a lot) to get Windows and Mac to cooperate.