Playing chess is great mental exercise, I would think the benefits of this would show up all over the place, including on the pool table. Being able to think quickly and clearly in order to plan an out pattern or think ahead in a safety battle is a good thing in pool, and concentration ability is absolutely crucial.
Also, the more training you can give your brain about this type of planning, the less mentally taxing it becomes. We all make mistakes as we become mentally tired; think of mental exercise (including chess) as a way to decrease the mental fatigue you experience during long or pressure-filled matches.
But, as Jude pointed out, I don't think it will directly teach you anything applicable to pool. Although some people compare 1-pocket to chess, the games ahve almost nothing in common strategically, except the fact that they are in fact games of strategy. I don't think there's anything strategic you can learn in one that applies to the other. Play pool if you want to learn pool. Play chess to learn chess, and to condition your brain.
-Andrew