Coral Hitchhiker?

I have a new tank that I've cycled with live sand and live rock. Since I went with all live rock it cycled pretty quick, so I think we were able to keep most (if not all) of the hitchhikers alive. Most of the hitchhikers I expected: small starfish, spionid worms, and a few very small fan worms. However, I just noticed today some very small, cream colored, tree-like branching organisms (photo link below). There are two of them.

Any help identifying them would be appreciated, as well as insight into whether they are beneficial or not. I've looked on the standard "hitchhiker guides" and haven't found anything like them.

Thanks in advance.

photo link: imgur.com/a/NQsni