It would be fine, if you are going to drink it in a month or so. The longer it sits, the stronger it gets. I wouldn't do it, but if you are making a quick drinking wine, it could be done. Otherwise, you'd want it in the fermentation instead.
It would be perfect to give as a new years wine to be consumed on christmas/new years eve or so. Maybe an alternative would be tying a cinnamon stick to the neck of the wine with ribbon for looks and possibly to decant the wine in.
the extraction from a Cinnamon stick can be very harsh,when I make my Holiday wine I start with a base say a plum wine,to that I add orange extract and to finish it off a Cinnamon extract this is all done by taste in a primary mixing pot ,the volume of your wine is the plum to that you add in proportion the rest and a tad of simple syrup if you would like,let it set overnight ,taste again, adjust then bottle..just the way I do it.