If a city has two knights for one player and one knight for another, does the player with two knights get the double point bonus for that city?
When the city is completed, the player(s) with the most knights in the city gets points for the city in the amount of two per tile plus two per banner. No other player receives any points for that city.
For example, when completing a three-tile city without banners, the player with two knights will receive 6 points, and the player with one knight will receive none, just like if there was only one knight in the city.
- In the event of a tie, each of the players tied for the most knights gets all of the points.
- Half that for incomplete cities at the end of the game.
A city is complete when it is surrounded by walls and there are no gaps in the walls or the city. There can be any number of sections in a city. A player who owns a knight in a completed city scores 2 points per tile in the city (count the tiles and not the sections). Each banner in the scored city also gives the player 2 points.
What if there are more than one follower on a completed road or city? With some clever tile placements, it is possible to connect road and city sections, resulting in a road with more than one thief or a city with more than one knight. The player with the most thieves or knights scores the totality of the points. In case of a tie, the tied players each score the points.
During the final scoring, incomplete roads, cities or monasteries are scored. A player who has a follower on an incomplete road, city or monastery scores 1 point per tile. For cities, each banner is also worth only 1 point. In case of a tie, use the same rules as for completed features.
(Emphasis in original)
If by double point you mean banner or other point influence in an expansion, yes. The winner of the meeple showdown wins it all, no divisions except in case of ties.