Getting to and from Baguio is pretty straightforward with many vans and buses plowing the route.
From Vigan:
If you’re coming from Vigan, take one of the many buses each day to Baguio (6:00, 6:30, 7:00, 7:30 & 9:00 – 324p).
To Banaue:
As of just a year ago, there are vans that go from Baguio to Banaue. They depart at 9:30am, the ticket is 415p and the travel time is about 7 hours with stops. The van is a great option. It takes a different route than the bus does, passing through Sagada and Bontoc, climbing through the mountains and valleys with spectacular views of the rice terraces along the way. You’ll get to know the other local passengers very well and the the van will even make special stops for foreigners to take pictures!
There is also a big bus (KMS) that goes from Baguio to Banaue, the cost is 415p, departing at 8:00am and 9:30am, it takes at least 8-9 hours to get there.
The KMS station where you would buy a ticket, and where the bus departs from, is located at: Chanum Street and Lake Road. The van departs from the road just behind the bus station, Benjamin R. Salvosa Street and Otek Street.