If you're staying the bar area, casual clothes are ok. For dining, you may want to avoid short pants, no sleeve shirts, sandals, etc.
It is probably contingent on whether we're talking about lunch, or dinner. They are a fine dining establishment, and business casual should be acceptable. But, when in doubt call ahead and ask about their dress policies. A X-mas dinner should be more semi-formal attire.
It's fine dining.........
I was casually dressed when I went. I had on a maxi dress that wasn't too dressy. I went on a haunted pub crawl that met there. People were wearing Jean's, shorts and dresses. Hope this helps.
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