I stayed at the Sheraton there about a year ago. It was OK on the Club floor. Lisbon is similar to Spanish cities in some ways and the hotels are one example. The Sheraton is in a business location and you'll probably need a cab to get to the busy nightlife area which I can't remember the name of.
I do recall the name of a great seafood restaurant near the water called Cais de Ribiera. The waiter will bring you to a huge tray of ice with all the catch of the day lying there so you can make your pick. It seemed quite popular even though I was there on a Tuesday night.
I do advise calling for a taxi if you leave the restaurant late and have to walk by the train (or is it bus?) station. There can be some roughnecks and cutpurses around there. I didn't have a problem walking by myself, but with Brigitte in hand I might be more careful.
I wish I also remembered the name of another restaurant we went to which was old-world Lisbon, but the Concierge recommended it to me so I'm sure he will do the same for you.
I was there on business so I didn't get to the cultural sites, but I was assured that there were plenty.
I tried PGA airlines which was very nice for short flights. Their biz lounge is nicer than most established airline lounges.
With Porto or Rioja you can't go wrong. I don't know what advice to give you except to trust your sommelier.
That's all that I can recall. I was only there for a few days.