From 6 April the X6 bus service in Failand will be half-hourly (the current service is hourly).
The new timetable can be downloaded here:
https://nationaljourneyplanner.travelinesw.com/swe-ttb/TTB/EFA01__0001b26_TP.pdf
This really makes the bus a viable alternative to a taxi as average wait time would only be 15 minutes.
The main limitation is that there is no direct route to Long Ashton, Backwell, Nailsea, Portishead or Weston. You have to take the bus to Ashton Gate and then get another outward to your destination.
X6 bus route: