How reliable are such numbers? They probably are derived from interviewers asking travellers 'how much they spent during their stay', with the latter inflating such expenditure figures. (I know, cause I went through such an interview by Tourism Malaysia years ago.) - I guess, it's a bit like a bloke being asked 'how big is your member'. He will (most of the time) say that it is bigger than it actually is.
In the past I've seen plenty of Chinese tour groups around the world, in Europe, Down Under, Hong Kong, and Thailand. And they always seem to spend money at the same hotels, restaurants and tour companies.