Context: Content type Person has reference (multiple values) to a content type Work, using entity reference.
Need: To display the title of each person node which references a given work, separated by a comma.
Done: A view with a back reference, the right nodes are fetched. (Views 7.x-3.7)
Problem: Cannot display the value separated by a comma. Note: I usually do it with the "Simple separator" display type which is under "Display all values in the same row" in the MULTIPLE FIELD SETTINGS field group. However, this field group is not available in my context.
Solved
I have found the module Views Merge Rows - works very nice. If it does not support Features module for some reason, I can take some of its code code in order to use hook_views_pre_render myself.
I had a similar issue, where I was using the Entity Reference relationship of "Referencing Entity" instead of "Referenced Entity". (The reference was on the child and the View started at the parent level).
When you run a Drupal System Message on the row (dsm), it returns all the nid responses appropriately, but as different result rows instead of as a single object; however, since the NID field (like many others) has no option for display multiple results, it would only grab the first result.
I ended up having to do an Entity Query from a Views PHP field with the current row's NID as one of the Field Conditions. That seemed to do the trick, rather than trying to load a View inside of a View with views_field_view.