Add a Collaborative Report in my CV
These kinds of grey literature are often included in CV's but it's important to be clear about the nature of the publication.  I would put this after any peer reviewed journal articles and conference proceedings papers in a section titled something like "technical reports and other manuscripts."   If you don't have any other publications, then it may make sense to simply describe the project (and what you did on the project in particular) and mention in passing that you were a coauthor on the project report.  

For someone just applying to a PhD program, this will look good on your application and certainly shouldn't hurt.