It's well documented of late that he's ready to come to the Prem:
The Colombian said: "There is a club that I dream to play for. They are foreign but I do not want to say who it is now. The Spanish league is good, but I prefer the Premier League as there is a better atmosphere on the field."
I think most expect he's referring to being reunited with the new Chelski boss.
That said, and considering both he and his club know he will leave this summer, I definitely think he's worth talking to.
He'll cost somewhere in the region of £27m but he's excellent so come on City, if Aguero isn't going to happen (or even if it does!), start talks.