Is urine good for compost bins?

No, urine isn't very good. Although poop is a useful material in compost pile it's very stinky.

-Super Llama

edit:

Both feces and urine are good in compost. It should be noted that the bacteria found in feces takes a great deal of time to disappear in a compost pile (at least 2 years in warm climates). Feces contains biological matter that humans do not digest, that can be further broken down in the compost pile. The urine contains nitrates and phosphates which are beneficial for plant life.