Certainly this is the usual situation for the Cisco and Avaya phones I'm familiar with, as it's usual to keep voice and data traffic separate.
This is from a Cisco SPA504G phone web configuration; these facilities are available through any of the methods for configuring them, through their remote provisioning mechanisms (HTTP/TFTP etc)
You see that the phone VLAN and the PC port VLAN don't necessarily have the same value.
What make and model of phones are you working with? That would be helpful.
Jonathan.