https://www.talksox.com/forum/threads/18223-From-Chicago-visiting-Fenway-this-weekend?highlight=Fenway
First, read the previous threads where this has been brought up. See above.
Honestly, anywhere in Boston is close enough for your wife and yourself to tour. Not sure what your price range is but the Fairmont Copley is in a great location for all sightseeing and close enough to walk to Fenway. Getting around town will be really easy as you can just walk or take the T. Boston is a very small town and walkable.
There are a bunch of Bars near Fenway and along Boylston near Copley.
I wouldn't rent a car. Either take the T or walk.