Here’s a quick chart that I created based on reading up from different sources about licenses required in office 2013/office 365 to use Power View and/or Power BI. It was not straight forward and I had to use multiple sources to find this information, so hopefully this helps you:
Double check w/ official sources. The chart is meant to guide to find the right license for your needs. Please use this as a starting point & use official resources before making a purchase decision.