The Watchtower improvement doesn't apply the initiative bonus for defenders during combat, nor is the bonus shown in the city details like the other bonuses. I had a look in the xml and think I found the likely culprit.
This is how the code is currently written:
Code: xml
- <ModType>CityTrainingBonus</ModType>
- <Attribute>AdjustDefendingUnit</Attribute>
This is how it probably should be:
Code: xml
- <ModType>City</ModType>
- <Attribute>AdjustDefendingUnit</Attribute>