Make sure you spell the name correctly. It’s Bellano,
Bellano is famous for the Orrido (Gorge), which is certainly a place to consider visiting regardless of which town you choose to stay in.
What you mentioned is correct. The boat service to Bellano is not as frequent. In the midlake Menaggio, Bellagio have the absolute most frequent boat service, followed by Varenna which is not as frequent but much more frequent than Bellano. All three towns also have the car ferry, which adds more choices, even though you may not have a car. Basically most boat runs from the south start from Como and stop as far north as Varenna (without reaching Bellano) while the ones from Colico, which also stop in Bellano, are few. Both Bellano and Varenna have train service as well.
From a logistics standpoint, I would stay in one of the 3 towns I mentioned: Bellagio, Menaggio, Varenna. Which of the 3 is up to you. Varenna is quaint and small. Bellagio is quaint and a not as small, but also the most crowded, being the most famous. Menaggio is quaint and a bit larger.