Hi Charles,
I cannot answer for CC2564 and giving you a fair figure for connection establishment will be hard as it depends on several parameters. What I can tell you is that using CC2541 as one chip solution will significantly improve power consumption compared to a dual chip (CC2564) solution as no processing due to serial communication is needed.
I believe you'll find some useful information on our wiki (www.ti.com/ble-wiki).
I suggest you clone this post to the Bluetooth forum to get some answers on the CC2564.
Best Regards