We will spend two nights in Bacharach and two nights in Beilstein. . . . . . any restaurants or bakeries not to miss along the Rhine and Mosel?
Eat at least one night in Rüdesheim. Not because the food will necessarily be anything special (it may or may not), but because many of the restaurants feature live Schlager music nightly. You'll also see many bachelor and bachelorette parties from Frankfurt, Wiesbaden and Mainz drinking their way through the town at night. Have some wine and make a new best friend for about an hour!
I find German bakeries to be uniformally excellent, but they're all pretty standard. Just pick one at random, and you probably won't be disappointed.
We stayed at the Hotel Haus Lipmann in Beilstein a couple of years ago and their restaurant served delicious traditional meals. There is another restaurant next door, the Altes Zollhaus Lipmann, where we had a lovely lunch. And, if you still have room for dessert, the Hotel Haus Burg Metternich served a to-die for apple strudel!
We definitely ate well while we were in Beilstein!
Live Schlager music in a restaurant is something I've never seen in all my trips, only at a festival in a park, in the Altstadt of a city, or at a Schützenfest in a town. Most likely, seeing a band doing their Schlager music routine in Rüdesheim may be touristy, but why not. Good suggestion! It's the music you came to hear not seeing the tourists.
Fred, if it was for tourists, they would play Blasmusik. As noted above, it's intended more for the somewhat pickled pre and post wedding parties from the surrounding cities (one's enjoyment of Schlager tends to be inversely proprotional to one's sobriety). I doubt most tourists would even recognize it as an indigenous German(ic) music genre.
In Bacharach, try the Cafe Rusticana. Very friendly owner (speaks excellent English). Apple strudel is excellent. Located on the main street. Not much of a sign to identify it so look closely.
Bacharach has a number of small restaurants to eat in, including Hotel Kranenturn.
The Konisbacher Brewery south of Koblenz (north of Bacharach) has a little beer garden beside the Rhine River that serves food. It's one of my favorite places to spend a nice afternoon watching the tour boats go up and down the river.
The best apple strudel I have ever had was at Altes Haus in Bacharach .
I second the Hotel Haus Lippman recommendation. We stayed there several nights and the meals were very good, tasty, and well served. We usually ate out on the terrace under the grape vines, looking at the river.
Not sure where along the Mosel you're heading, but we had a wonderful meal at a small restaurant in Kobern-Gondolf called Die Alte Muehle. It's easy to miss because from the street all you can see is a stone wall if the gate isn't open. And when the gate IS open it's not a real big opening. But the food was excellent, and the atmosphere very conducive to a quiet and enjoyable meal. There's an outside courtyard (inside the stone wall) and indoor seating in the old mill.