Ok, I don't use Message. Facetime can be real picky about what's in your hosts file (the mac one). Look in /etc/hosts, it should look like this:
It's possible the VM is keeping you from using it. Also be aware installing Yosemite (or any other mac OS except server) into a VM, on any platform, is against the EULA. (not here to preach, just be aware)
# Host Database
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.