I found this:
Q. I want to have additional servers running Windows Server 2008 or Windows Server 2008 R2 in my SBS 2011 Standard domain. Do I need additional CALs to access those servers? A. No. As long as those servers are within the Windows Small Business Server 2011 Standard domain, your Windows Small Business Server 2011 CAL Suites grant you access rights to the other Windows Servers. Note however, the use of some functionality in Windows Server require additional licenses (e.g., Remote Desktop Services/Rights Management Services).
Here. I'm looking to find out if the CAL would also cover a Server 2012 or Server 2012 R2 member server of the SBS domain as well. Has anyone found anything from Microsoft one way or the other?