Purchasing resources from other cities in the region seems to be key in the most recent SimCity. Obviously, my first city had to be self-sufficient, but then when I built my second city, I was able to just purchase the power/water/sewage treatment from my first city, and just upgrade these services in my first city as the second city expanded. However, when I tried to do this when my third city, it doesn't seem to be working.
You can see from the screenshot below, that even though there seems to be power available from Monet Plateau (my first city), my third city doesn't seem to be making use of any of that (and it definitely does need it - this happens to be why the city button is highlighted yellow). Any idea why this might be occurring? Could it be some sort of bug? I, like everyone, am having connection issues.