Using latest patch: utilizing a general to form a citadel does not increase supply. My supply was 15/12 before citadel, and remained 15/12 after creation of citadel. In my latest game, i have been riding 1 to 3 over my cap for over a dozen turns.
I am in second place for tech lead, 2 under the leader, 2 above the third in tech.
I am not sure that the burden of tech on supply is a bad thing, but the issue for me is that none of the steps that are meant to mitigate those effects seem to be working for me. Citadel doesn't work, walls don't seem to effect it (although that's a percent, not an integer value, so not easy for me to test), Great wall might have affected supply but not sure. Citadel doesn't, and barracks again don't seem to (difficult to test).
I have this problem too. So bug is still there. I had supply 10/10 then used great general for a citadel but supply still 10/10. The game is saying supply is increased by 2 but it is not.