The general rule is that the travel guarantee always applies. If the deviation is announced in advance, or if you knew or should have known, that the deviation was not caused by AtB, we can not offer a refund.
The travel guarantee applies to all AtB bus lines (not the Night bus, Gråkallbanen - tram and ferry/boat).
The travel guarantee applies to single trips and when you transfer with correspondance during a journey. You must allow enough time in addition to the required time if there is no fixed correspondence in the timetable.