Well, that's not really how I read the question. The rule book is very clear that each "City" gets one action per turn, whether building a building or unit, harvesting a resource or devoting to the arts. What it sounds like he was asking was if you use a resource ability from a tech, do you also get to do your action for that city. What I was saying was that resource abilities are not an "action". You can use the resource abilities of all your techs "once" during your turn. It's just when you can use that resource ability. If you have 3 techs that say "City Management", and you have the resources available, you can use all three during the City Management. Here's an example:
I have 2 cities and currently have 1 incense resource in my reserves. I also have unlocked the following techs Currency (Incense: Gain 3 Culture) , Chivalry (Incense: Gain 5 Culture) and Metal Casting (Incense: gain 7 Culture). Also, I am on on the second mark on the culture track and have 2 Culture cards in my hand. It's now my turn to do the City Management phase.
I have Incense available to harvest in both my cities. I do that and now have 3 Incense available to me. So I use all three to use all three techs to end up with a total of 15 Culture (assuming I had none to start with). Now, it's still my city management phase, so I decide to spend all my Culture to move on the track. I spend 3 and move 1 spot to the Great Person mark. I get my random great person and place him on a legal spot on the outskirts of one of my cities. I spend 3 more, go up a mark and get a Culture card. Then I have to discard a culture card immediately (unless I was able to use one before I went up on the track). That leaves me 9 culture. Let's assume I still can't play a culture card (they are all "Start of Turn" culture cards). So I spend 3 more culture to go up another mark, get another card and immediately discard one (even if I drew a Culture card that allowed me to play it during the City Management phase, I would have to discard first before playing it). So, let's say I did draw a "City Management" culture card. I would discard a card (likely one of my "Start of Turn" cards) and then I could play the "City Management" card. Now I am down to 1 culture card and I have 6 culture left). So I spend 3 culture to go up a mark and draw another culture card. Since that gives me 2 cards I don't have to discard. If I drew another "City management" culture card (or an "Anytime" culture card), I could play it. Let's say it was another "Start of Turn" culture card). I have 3 culture left. I spend it and go up again on the culture track to the Random Great Person. I draw a Great Person and place him in another legal spot near one of my cities.
And, I'm done. I've spent all my culture and went up 5 spots on the culture track (next time I try to go up will move me into the Culture Event 2 so it will cost 5 Culture and 3 Trade to go up). So, while you only get 1 "City Action" per City, per turn. You can actually take several actions during the "City Management" phase.