To my understanding this is only half correct: The companion has to fly all segments with the Senator but not v/v. Since my wife lives in Berlin and I in Duesseldorf I regulary book on all i/c award tickets:
DUS - TXL - FRA - Intercontinental - FRA - TXL - DUS
for myself and
TXL - FRA - Intercontinental - FRA - TXL
for her. This works perfectly with companion awards