must i get both the SharePoint Standard CAL and the SharePoint Enterprise CAL to have access to the Enterprise edition features of SharePoint
Yes. It says that exact thing in the licensing information here.
SharePoint Enterprise CAL is additive: to access the Enterprise edition features of SharePoint, a person/device must have both the SharePoint Standard CAL and the SharePoint Enterprise CAL.
So all users need a standard CAL. If you are also using enterprise features then users must also have an enterprise CAL.