With a Power BI Premium license, you can create a hybrid deployment mixing cloud and on-premises. See Microsoft Volume Licensing for details. Power BI Report Server is available through two different licenses: Power BI Premium and SQL Server Enterprise Edition with Software Assurance.
See Comparing Power BI Report Server and the Power BI service for details. Power BI Report Server features are a superset of Reporting Services: everything you can do in Reporting Services, you can do with Power BI Report Server, along with support for Power BI reports. Like Reporting Services, Power BI Report Server is on premises. Like the Power BI service, Power BI Report Server hosts Power BI reports (.pbix), Excel files, and paginated reports (.rdl). Power BI Report Server is similar to both SQL Server Reporting Services and the Power BI online service, but in different ways. Your users can access those reports in different ways: viewing them in a web browser or mobile device, or as an email in their in-box. Along with it come the tools to create Power BI reports, paginated reports, mobile reports, and KPIs. Power BI Report Server is an on-premises report server with a web portal in which you display and manage reports and KPIs.
