If I understand your question framing correctly..........
The Tetramax tool just generates the pattern which needs to be fed to your DUT and its behavior has to be observed.
VCS is a simulator tool using which you can see how your logic components toggle when the patterns pass through the DUT.
It has been a long time I have not used the tetramax and the vcs, but I think if the run_simulation is supported then this command can call the simulator. Here you can avoid manually calling the simulator/VCS. Please refer to the Tetramax command reference manual for details on how to do that.