Dolomites by tour bus-suggestions?

I hope there isn't.
No offense but nothing ruins a scenic spot more than a tour bus full of people all descending on it at the same time.

As it becomes more well known there probably will be.

Having been there in Sept. I don't recall seeing any tour buses.
There are definitely photo tours and other group tours that happen in the region but those folks all lodge together the entire time as well not just share a bus ride.

There are local busses that go from town to town so when can get around without a car in season at least. In the late fall those may not run.
Best option is to rent your own car and drive.

I do not remember seeing any tour buses either. The most beautiful scenery is from the hikes st the top of the lifts.

You can use public transportation to tour yourself. We never get a car. What part of this larger area do you wish to visit?

In June 2013, remember tour busses arriving at Alpe di Siusi in the morning. I think these were delivering German or Italian tourists for the day.

I spent some time in the Val Gardena this past summer. There was a tourist agency in Ortisei near the square (Sant'Antonio) where the bus hub was located that sold day tours which I believe included a drive through the mountain pass(es). I didn't take any of the tours but believe they were van or minibus tours. One of the tours was to Merano, another to a mountain lake, can't recall all of them. It appeared that different tours were scheduled each day. Getting to Ortisei by public transportation was simple so perhaps one or more of these day tours would work for you if you didn't want to use the public buses (truly a wonderful, easy option) or drive yourself.

Public transportation in that area is very good. The tourist offices in Otisei and the valley cities of Bolzano and Bressanone have a thick brochure that includes all train, bus and lift schedules in the area. It makes it very easy to plan sightseeing and walking/hiking jaunts.