They are both Equally Xenophobic.

I think Frollo is a bit more xenophobic. Frollo has been searching for gypsies since the very beggining of his movie. Opressing gypsies is the first thing we see him doing. Ratcliffe seems to be motivated more by greed than by hatred( which is by no means better). He didn't carry about Natives too much in the first part of movie. Sure, he was ready to fight them but didn't search for them purposefully. Genocide wasn't his primary goal( Frollo had genocidical intentions before meeting Esmeralda).
Ratcliffe is xenophobic but I don't think it's his defining trait. Selfish, unscrupulous and greedy defines him better.

I have to say, They are both Equally Xenophobic, Because I cannot choose one over the other.