大教堂应该记入城市块数量的。
请看以下BigBox2的规则截图:

这是一个例子(很凑巧这个例子和LZ说的情况一样):
城市包括6块(含大教堂)和2面三角旗,蓝色能获得24分
原规则描述:
Cathedral(2 tiles)
If one or both Cathedral tiles are located in a completed city, the knight earns 3 points per city segment
(number of tiles) and pennant. If such a city is not completed by the end of the game, the knight scores 0
points for the player!