Going in September with a group of seven (mostly related). Would like to visit from Garmisch and return the same day if possible. I did the Munich bus trip a few years back and seemed a waste of a day with all the travel when Garmisch is so much closer. A stop at the Weiskirche would be nice to fit in as well. We're traveling by train so no car available for us. Are there tours available from there or is it regular bus service? I can read the train schedule fairly well but the bus schedules elude me.
There is a regular scheduled bus that runs from Garmisch-Partenkirchen Bahnhof to Füssen via Oberammergau. Actually, it stops at Hohenschwangau bus stop, which is right around the corner from the castle kiosk about 5 minutes before arriving in Füssen. The German Rail (Bahn) website will show you these bus connections. Just put in "Post/Bahnhof Garmisch-Partenkirchen" to "Hohenschwangau". Or, you can read all the connections on a few pages here. That bus only stops in Wieskirche long enough to let passengers off. I went through Wieskirche in 2004. I was catching a bus leaving Wieskirche going the other direction, so I had an hour's stopover. It only took me 5 minutes to see the church, then I went across the street for lunch. I guess once you have seen one overly gaudy Baroque church, you've seen them all. The church at Andechs is similar to Wieskirche. In fact, I bought a postcard of the church at Andechs and one at Weiskirche. Without looking at the back, I can't tell which is which.
We did this a few years ago. MIT was a Sumday soothe regular service was not running. We took a train tomReutte and there was a special bus from there. The tourist office in Garmisch gave us the schedules and it all worked out great. We had a definite pickup time for the return bus, I think it was 3:15 but that gave us plenty of time for the casttle and also lunch. There was a huge crowd of people waiting for buses and it was a little unnerving as they all tried to get on our bus but it was the wrong bus for them and the driver had to yell at them to get them off. I hope for your sake that was an unusual situation.
There are buses from Garmisch to Füssen on Sundays, but the schedule is reduced. If you take the train to Reutte or Pfronten and spend the night there, there are regularly scheduled buses to Füssen and then on to Hohenschwangau. I would suggest you take the train from Garmisch to Pfronten and stay at Gasthof Aggenstein. There is a bus stop right in front of the Gasthof. That bus goes to the Pfronten Ried Bahnhof and either continues from there to Füssen, or you have to catch another bus. Either way, when you stay in Pfronten, you get a pass for the bus.