I have used that method with success many times. There are, in fact, tie lines, private lines, and signal circuits that are designed to do just that...rely upon a ground connection at each end...and they work perfectly using the only ground available at each end: the telco ground or electrical ground. As Sam said, there may be slight voltages present (usually in the millivolt range) but those are found when measuring the electrical ground to earth ground connections within a building. In the long run (so to speak) ground is ground the world around.

Arthur P. Bloom
"30 years of faithful service...15 years on hold"