Frequently, partners ask me about getting access to Power BI for a little longer than a trial period. Up until recently the only answer I could give was there was nothing available. However, there is news! Partners can now get access to Power BI through the Partner benefits portal. This blog explains it all: http://blogs.technet.com/b/uspartner_ts2team/archive/2014/07/10/power-bi-for-office-365-now-available-to-competency-partners.aspx
Hope this helps!