Hey, there is no command to my knowledge as such to show the interface speeds for a specific ap-group. You would need to need to run the command individually (or a bit of cut and paste!). Do you have access to the switch, I expect you can probably get this information from there.
Failing that the quickest command to view the speed of an individual AP is below.
(Lab620) #show ap port status ap-name AM-xx:xx:xx:xx:xx
AP "AM-d8:c7:c8:ce:c3:0c" Port Status (updated every 60 seconds)
----------------------------------------------------------------
Port MAC Type Forward Mode Admin Oper Speed Duplex 802.3az PoE STP TX-Packets TX-Bytes RX-Packets RX-Bytes
---- --- ---- ------------ ----- ---- ----- ------ ------- --- --- ---------- -------- ---------- --------
0 xx:xx:xx:xx:xx
GE N/A enabled up 1 Gb/s full N/A N/A N/A 633 121930 1763 186373