Sorry, I thought I'd replied to your question yesterday; just put it down to a 'senior moment'.
Paul is quite correct. The Arnos Vale Waterwheel closed down some two years or more ago - as far as I have been able to ascertain. However, the Arnos Vale Hotel is still operational, as far as I am aware.
To be honest, it’s impossible to get honest, accurate, timely information regarding this hotel/restaurant because they never respond to email. I will refrain from comment about the owner's, the Brontes, who also manage the place. They seem unable to keep a manager more than a few months. Just thinking about them reminds me of the controversial comments that Jeremy Clarkson made about striking public service workers on the One Show recently. The Brontes have allowed the most beautiful beach and environment on Tobago to go to rack and ruin.
The Waterwheel restaurant was run by the owner's son, who is a bit of a cross between Alan Carr and Graham Norton, but without the redeeming personality. I use the word 'run' advisedly, because one contact told me that it was more a matter of whether he bothered to get up and/or could remember where the restaurant was. I'm sure that's an exaggeration, but I do recall one horrendous case of a couple booking a table there, being dropped off at the car park by taxi after arranging to be collected later that evening, then walking down to the restaurant only to find it closed and deserted. Imagine being stuck down there in that dense bush for several hours with all the strange rainforest sounds and nothing but a couple of security lights for comfort.
It is such a crying shame that Tobago’s best resources are so often pillaged by wealthy people who lack the intelligence, commitment or foresight to make the most of their assets.