Your first city, which is the only one not powered has an infrastructure of 1060. A single oil power plant provides power for only 500 infra and you have two of them which means only 1000 out of 1060 infra receives power. Hence, the rest 60 infra is not powered.
I would recommend going for nuclear power, you can buy uranium at the trade market and one nuclear power plant powers the same amount of infra as four oil plants.