Yes, it could qualify as an event at RC.
Here is a link to the superficial overview:
http://www.ritzcarlton.com/en/Reward...dingEvents.htm
A number of years ago I knew that the minimum F&B charge at a RC for any event was $25,000. So the afternoon tea might be more than the OP wishes to pay in order to get points. For some reason when the OP says an expensive tea, I don't think s/he was talking about $25,000; but then again, maybe s/he was.