Feeder Towns?
Of course it is allowed.
Forum Discussion
If towns could trade donuts or items, I could understand not allowing multiple accounts, but at most a feeder town can give your main town event stuff (gremaliens now, spying during stonecutters, gift bags last xmas, etc) and tap whatever you might specifically want tapped. They're very convenient, but not game-breaking. I mean, you still only get 100 neighbors. So yeah, you can have however many towns you feel like. (One member here has a dozen towns. That's dedication.)
