Clearer licensing regarding SQL Server Enterprise Edition with Software Assurance.

I have read quite a lot about licencing on Power BI but I am still not quite sure whether we can use the free version of Power BI Desktop with Report Server when it is licenced under the 'SQL Server Enterprise Edition with Software Assurance'. Can anyone confirm? What I want to do is create reports using Power BI Desktop, publish them to the Power BI Report server and have other people in my organisation view the data, without needing their own licence. Is that possible or do we have to buy licences for the viewers? Thanks