Although this is rather interesting, I doubt Civ 5 (or any other Civ for that matter) has the capability to implement such a mechanic in a satisfactory way. If you just build units that give another city food/hammers or just directly transfer food/hammers from one city to another, that would be fairly awful. I'm hoping that they have some way to represent the supply chain and have it deteriorate with travel time (rather than tile spacing).
Also, wouldnt this be terrible for city balance, which is bad enough as it is? If we can have huge food only cities provide food for massive production centers, we would have even more unit production than before. I don't think Civ 5 needs anything more adding to the potential army carpet lategame.