If you want to go some where nice you at very minimum are going to need slacks, shoes (not runners) and a button up shirt or nice sweater. (Essentially office casual.)
Depending on your company you might be able to get away with that. If it's a date I would suggest adding a suit jacket. If you're going for dinner (as opposed to lunch/brunch) I would highly recommend a jacket as well.
If you hate neck ties, you can probably avoid them, but I think shirt/slacks/leather shoes is pretty non negotiable. Especially at the Wedgewood, where Bacchus is located.
Note: The food was fantastic last time I was there, and worth a bit of stuffy attire.
~ Just another noob looking for a clue