I don't know if this has been addressed previously, but I noticed in the game I was just playing (Antiquity, Trung Trac, Mauryan) that, when I built farms on some hexes with happiness bonuses (mainly flat desert), I wasn't getting the happiness bonus for my town, leaving me stuck at 4. I wanted to add an over-the-limit settlement, so it was a consequential issue. However, when I built a farm on a river tile in another town, I did get the bonus. Anyone have a quick explanation of why this happens?