Would policies be more interesting if the interacted with districts? There are a few right now that do and could be extended to more policies. For example:
Agoge: +25%
Production towards Ancient and Classical era melee and ranged units. Increases to +50%
production with an encampment.
Colonization: +50%
Production towards Settlers. Increased to +50%
Production towards Settlers with a Harbor or Commercial Hub.
Praetorium: Governors provide +2 Loyalty per turn to there city. Increased to +3 Loyalty per turn to there city with a Holy Site or Campus.
Agoge: +25%


Colonization: +50%


Praetorium: Governors provide +2 Loyalty per turn to there city. Increased to +3 Loyalty per turn to there city with a Holy Site or Campus.