Power BI Report Server On Premise Licensing

Hello,

I'm sorry if my question has been already adressed but as far as I know, I didn't the answer to my question.

We have purchased a Power BI Premium license A4/P1 SKU and we have already installed a Power BI Report Server on Premise on a virtual machine which has 4 vcore. We would like to install another instance of Power BI Report Server on another virtual machine in order to make clear separation of use between two separates entities in our organization (obviously we'll need also separates databases but that is not a problem). What are the limitations in terms of licensing ? For example, is our Premium license enable for 8 vcore and so we can install another Power BI Report Server Instance in a 4 vcore VM ? 

Thanks all for your help,

Alex.