The Meisterwerke der Mosel tasting can be a bit of a scrum. I don't bother: enough energy is required for the pre-auction tasting, for which my only advice is "get there early" based on the crush in recent years.
Been to Schloss Monaise many times over the years. Can be chaos on the pre-auction night, especially if the chef gets interested in the wines rather than the cooking. A short taxi ride from Trier. Okish at best.
Schanz (**) mentioned by Chiu is the choice of fine dining. I've been there with a UK group the last few years, including last year pre-auction, when it wasn't overrun as too distant from Trier. The drawback is that it is in Piesport, quite a long taxi ride from Trier. Of course great to have Julian Haart Kabinett here, but there isn't much left.
Becker's (**) isn't the level of Schanz foodwise. No rush to go back there for me.
Eurener-Hof has plain food, with plenty of game, again a short taxi ride from the centre. It used to have a good wine list, but the previous bargains have mostly been drunk by Russell of these pages.
Das Wenhaus is good to sample recent vintages at modest prices. Be careful of bottles that have been stored in the restaurant for some time: most things are just stored along the wall.
Von Kesselstatt is a good place for a beer and simple food, a regular lunch place with friends on auction day but needs someone to drive from the current auction venue. It is often beautiful weather in mid-September to sit outside. Not fine dining. Never been in the evening.