We also had a good meal last week at La Taverna and their wine list is somewhat intriguing. Other than that the slow guide is great and we ate in several other places in Umbria including Montefalco and Montone and never had a bad meal at a Tratoria or Osteria. Even cafe food for light snacks were good.
Enjoy its a wonderful place but getting hot now.....it was around 30-33 celsius last week.

Spoleta is wonderful and you will enjoy your stay there. Don't miss going to Orvieto when you're in Bolsena...the cathedral is spectacular as is the town and its wine.