ya, i haven't heard anything good about gorilla glue...
i generally use G2 epoxy...it is awesome stuff...cures in a day at room temperature, 60 minutes working time...which allows me the fuss-time i need when bending in a form
but having said that, i have also used simple yellow glue and had no troubles yet...
and i did a water test on my yellow glue. It took 6 hours of complete immersion in water for the pieces to come apart...and even then, i had to pull them apart...so i think that yellow glue should do you fine, provided you take steps to shed water from the bow when it is finished.