The Expres 4 (E4) bus line connects the Traian Vuia Airport to the Timișoara city center (Bastion).
The Expres 4 barat (E4 b) bus line connects the airport directly with Timișoara North Railway Station. This line stops in the centre of Timisoara (Bastion) as well.

The buses run approximately once per hour. See timetable and routes for E4 and E4b to and from the airport here
Payment methods see here