There's no max, but there is a minimum. I always account for an accidental 18v source accidentally being plugged into a pedal so I never get electrolytics below 25v. If I'm building a pedal with internal charge pump I try to go 35v+.
Technically I guess there's a maximum since generally as voltage goes up so does size of the cap. Most electrolytics 25v and below tend to be 5mm in width, which is what you want for most pedals. After 25v you start to see more of the 8 and 11mm caps so just watch out for physical size as you're ordering
