How to use view's relationships to pull user entity reference data?
There is a Relationship that introduces "backwards" Entity reference info into the Views. 

In Drupal 7 that is called something like this (you can find this in the list of Relationships in your Content Views under the Entity Reference Category):


  Entity Reference: Referencing entity
  A bridge to the User entity that is referencing Content via field_[myERfield]


After you have that you will be able to add the User: Name field, it will automatically use the above Relationship, and it will show which user referenced that particular node, for your each Views row.  



In Drupal 8 the Relationship is called 


  User using field_[myERfield]
  Relate each User with a field_[myERfield] set to the content.


The procedure is the same, you can now add Fields or Filters relating to User fields/data, if they're set to use the Relationship the user shown will be the one referencing the content of that Views row.