Can you use the green Mosque tile more than once per turn?
According to a thread on boardgamegeek.com about the same question: 

You can use this ability only once per turn.

Grzegorz Kobiela (who is credited as English translator of Istanbul’s rules) and André Bronswijk (who works for Istanbul’s publisher Pegasus Spiele) both confirmed this.

The reasoning is: You can use this ability when using a Warehouse, and you only use a Warehouse once per turn.

It’s probably an oversight that a clarifying "1x" is missing in the rules for the green tile (or that it was added to the rules for the red tile, which follows the same logic).

(For reference, another thread about it.)