Make sure BlueTooth is turned on in the Rezound, go to Settings-Bluetooth and make sure the toggle on the top is turned ON.
Now but the speaker in Pairing Mode:
Putting ClarityHD Precision Micro Bluetooth Speaker
Into Pairing Mode
1. Turn the main power switch on the back of ClarityHD
Precision Micro Bluetooth Speaker to the “ON” position.
2. Press and hold down POWER the button on the right side of ClarityHD
Precision Micro Bluetooth Speaker until the light on the front starts
blinking red and blue. This indicates that it is in pairing mode.
Note: ClarityHD Precision Micro Bluetooth Speaker will stay in pairing
mode for 3 minutes. If you do not complete the next steps before then,
simply turn ClarityHD Precision Micro Bluetooth Speaker main power
switch to OFF and then back to ON, and repeat step 2.
Now in the Rezound's Bluetooth Screen, press MENU-Search for devices, then the speaker should pop-up in the list as "ClarityHD", press it and it should pair up and ask for a passcode, enter 0000 and press OK, should be good to go now!
One of my co-workers has one of these, works OK... Not a fan of the sound (or maybe it's just his music

) but it pairs up with no problem and he has had it for several months.
Speaker manual:
http://www.monstercable.com/lit/LIT_Instr_ClarityHD_QS_BlackBerry_A6Ln.pdf