We will be traveling from Barcelona airport to Tarragona. I am looking at the pros/cons of bus vs. train. I know the Plana bus would require no transfers but the train actually gets us closer to where we want to be on the other end (yes, I know Tarragona station is the slow regional train vs. the fast train station being farther out of the city). There is also the benefit that the train leaves from Terminal 2 vs. having to take the shuttle to Terminal 1 to catch the bus.
My question is around buying tickets for Rodalies. If I buy a single ride ticket at the Airport for the R2 train to Sants, then transfer to one of the trains going to Tarragona (R14, R15, R16), do i have to buy another ticket or can i transfer with the same ticket? Also do you have to pick/reserve a specific train or does it work more like a long range subway?