When it comes to broadcasters and their advertisers milking and exploiting the masses of unthinking, herd following united "fans" particularly throughout SE Asia then I'm afraid City are still virtually a non-entity and irrelevance in commercial terms despite the trajectories the two clubs have taken in the last decade.
A lot of it is quite simply due to the colour of their shirts... red is considered a lucky colour throughout much of that part of the world and the largely uneducated and superstitious folks there will do anything to associate themselves with the colour red, including supporting who ever happens to be the most famous football team that plays in red which still happens to be united despite 10 years of failure and underachievement.