Priority queues should be covered in a competent introductory data structures course. Bloom filters are marginally more obscure, but I still expect a good candidate to have come across them at some point. They're so widely used that it's pretty hard to avoid learning about them if you've done any significant amount of work or just spend time reading HN (they come up in someone's blog every month or so).
Note that I said "would hesitate to", not "wouldn't hire". If someone were otherwise a strong candidate, but happened to not be familiar with these, I would almost surely still hire them.
I should clarify that a typical candidate for a junior position on my team is either coming from graduate school or has 3-5 years experience in industry. I have correspondingly higher expectations for their background knowledge.