NRT to Chiba City is 47 minutes by train - and train frequency is not so great - so it's not more accessible than Tokyo. It's just my opinion, but I don't really see the attraction. This is the Chiba City tourism page:
http://www.chibacity-ta.or.jp/englis...ide/index.html
Given the choice between spending some time in Narita City or Chiba City, I'd plump for Narita. It's a small town, but it has a temple (quite a noteworthy one), gardens, restaurants...