In most circumstances, there’s no issue when you happen to include a copyrighted art work in a photo. That is, until you attempt to sell it.
I have done this, in a sculpture museum in Queens, NY (it’s in my Flickr stream if you’re curious). I’ve had a travel site ask to use one of them, but I’ve never sold or even attempted to sell any of them. In hindsight, that was a smart move on my part.