We can acheive that by configuring two mac auth profiles.
1. We need to change the way mac-address format will be stored in the internal database using the above profile.
Eg: MAC-auth profile 1:
use delimiter as colon and case as lower
MAC auth profile 2
use delimiter as colon and case as upper
2. We need to map one these profiles to AAA profile in use
SSID 1: AAA Profile 1 mapped to MAC Auth Profile 1
SSID 2: AAA Profile 2 mapped to MAC Auth Profile 2.
3. Enter the mac-addresses in the internal database as per requirement (as per mac-auth profiles)
Note: As Colin mentioned earlier, mac-address is not secure.
The above config will help in acheiving the goal to an extent.
However, if there is a mac-address which needs to connect to both the SSID's, then more config/overtime is involved.