Is any picking style that uses alternate bass called Travis picking or is it a particular pattern?
Travis picking
Is any picking style that uses alternate bass called Travis picking or is it a particular pattern?
Travis picking is a specific type of fingerpicking pattern named after Merle Travis who populaized it.
The 2 essential elements are alternating bass & treble melody. Anders does a great job of demonstrating basic Travis picking technique in the Acoustic course.
https://www.guitartricks.com/tutorial/2495/
It's possible to play an alternating bass figure with other notes such as chord tones that don't really amount to a melody. Often because the guitar part is intended to be an accompaniment to the melody being sung by the vocalist. Whereas, often with Travis picking the approach is used instrumentally, so the guitar carries the melody.
However, there is a lot of overlap in the application of the concept & I've seen many people call Travis picking, just fingerpicking and vice versa.
Hope that helps!