We're limited to ipv4 so even if you hash it you could still test every possible address within a few minutes. You can even do the same with the bloom filter, since there's at worst only a 1/1000 false positive rate (and likely much smaller). The bloom filter isn't designed to provide security, and trying to make (ipv4) IPs private if you're using them as identities is a lost cause.

With a known structure, a hashed IP could be reversed quite easily couldn't it?