Jaguars production does not require Iron to be hooked up, but at what cost? Iron is plently on most maps types, especially in most commonly used climate types. In most of my Immortal games on Pangea Temperate climate maps, almost all AIs had Iron in their proximity. I opened many maps with the world editor and almost all have Iron somewhere not further than 8-10 squares of the starting location.
Furthermore, the AI rarely searches for IronWorking first and does not know the location of the Iron before you do. Hence, the probability of him settling the Iron is rather low. Even if it settled the Iron by chance, you still could do an immense archer or chariot rush to capture the Iron city and switch to swordman-based unit production.
Therefore, the only good things about not requiring Iron are:
1) No need to research the wheel to hook up the Iron. A minimal plus considering you will need Wheel technology anyway to hook up other resources and to grow your city.
2) No turns wasted in hooking up the Iron with workers. Hooking up Iron would mean:
a) settling your city near the Iron (you would have settled near the Iron anyway to take advantage of the +3 hammer bonus, so it makes little sense not wanting to settle near the Iron)
b) Time required to build the mine=12 turns in Marathon (again negligible, you would have mined the Iron anway to take advantage of the hammer production bonus)
c) hooking up with roads, approximately 6-12-18 turns with a single worker. I am only counting the time lost connecting the Iron to one city, because you would have connected the 2 cities with roads anyway to create a trade route.