In Brave New World what increases the delegate count for the World Congress/United Nations? Is there anything I can build to get more votes?
The base number of delegates each Civ gets is based on the era. The host of the congress starts with an extra delegate, which increases as the base number of delegates goes up during the Eras. The host is voted on again each time the congress enters a new Era. Once the Industrial Era has been reached, city-state allies provide additional delegates.
According to in-game Era-change pop-ups:
The Forbidden Palace Wonder gives +2 delegates.
The Globalization technology gives +1 delegate per spy assigned as Diplomat you have in another Civs Capital City.
If the World Congress enacts a World Religion, you get +2 delegates from being a member of that religion.
If the World Congress enacts a World Ideology, you get +2 delegates from being a member of that ideology.
You can also trade votes with other Civs through the Diplomacy screen.
There are a few ways that you can gain delegates throughout the game.