What would hurt, however, is running the bass into a guitar amp. While you can get away with it at very low volumes, a guitar amp is not designed to the frequencies a bass guitar produces, and you could damage a guitar amp when using a bass guitar at moderate to high volume.
They do make wah pedals that are specifically designed for the low end frequency response of a bass, but if you like the way you guitar wah sounds, I'd keep plugging away.