Seem to remember from my ATPL days that VHF range can be calculated by:
Range = 1.25 √height (ft) of tx + √height (ft) of rx
Resulting answer is in n.m.
So if you were 1000 ft and the other aircraft was also in the circuit at say 500 ft then the theoretical range is approx 60 nm.
So in your example it would be unusual for a vhf transmission to go that far, must be an atmospheric anomaly or it must be getting relayed somewhere.