Yes, my Portuguese camino app says it is 96.7km from Vigo. I assume that is from the Cathedral, and it would be very easy to add a few kilometres by catching a suburban bus or taxi southwards towards Ramallosa, which is really a suburb of Vigo. Make sure you do get a stamp from your starting place - and that it is on an official camino route. Vigo and Ramallosa are on the coastal camino.
The central route is to the east of Vigo, and bypasses it, although it goes very close to Vigo airport. The first town after Vigo airport is Redondela, which is only 83km from Santiago. On the central route, O Porrino is 99km from SDC, according to my app.