Thanny, you don't need to work a resource to get its benefits. Edit: Okay, gang, here's the scoop. Did a Worldbuilder Test: I gave myself Iron Working and Sailing, created a Lake, then hemmed an Iron in with Mountains. City A was on the opposite coast (capital). I founded City B on the Iron, and receive its benefits automatically. However, if I found City B outside the mountains and put the Iron in the fat cross, then Mine and Road the Iron, the benefits are not felt. I checked the Trade Blocs to see if it was a bug, but it was a different trade bloc entirely. Conclusion: If a resource is "hemmed" in by Mountains and/or Coast, to receive its benefits, one must settle atop the resource.