The problem sounds a little like collaborative filtering. If you have a certain affinity with cities A,B,C, then you can compute the expected affinity with a city X by looking at the affinities other people have with X, and their affinities with A,B,C.

Instead of looking at people, you can also scrape websites to get the relations. But here you may get a recursive problem because if a website speaks of "London", you might not know in advance which London they speak of.