In the interest of giving credit where credit is due, my avatar is a scan of a hand-drawn caricature by cartoonist Jim Naylor which was done at my company's 20th anniversary dinner.
For me it's not clear from the rulebook. Can Bruno jump in?
For me it is clear from the rule book.
Queendomino rule book, p4 on Building Bonuses wrote:
Lower right corner: Value of a building at the end of the game(Added emphasis mine).
On some of the Building Tiles, a symbol appears on both sides, in the lower right corner, showing the number of points that this building gives your kingdom at the end of the game.
Each building gives the bonus. Two statues gives you 10 points, 5 from each. Each building with the detached territory bonus each give you 2 points per separate territory of it's type - so if two are for the same type they still each give their bonus.
Queendomino rule book, p6 on Value of buildings in towns: wrote:
To avoid errors when calculating Building Bonuses for the red town territories, pull any Building Tiles you constructed off their squares one-by-one and add up the points from the lower right corner symbols as you go.
This say to score each building one-by-one. So if, for example, you score one building for three separate wheat territories and get 6 points; and then have another building that score for wheat then you add another 6 points - it doesn't say to ignore duplicates.
I suspect that the problem the people have here is either that they think of these bonuses as "special powers" that make the territories "worth" two points - they don't. These buildings generate their own points, based on the territory types in your kingdom, and so each such building generates its own 2 points per detached terrirtory.