XBEE WiFi S6B RSSI for Smartphone localization
Just incase anybody stumbles onto this page googling, I am posting my solution below (I think it will work for any xbee radio)

Basically for some reason the RSSI values are getting nulled out before I can read them, both in my API mode tests and AT commands.  I'm not convinced that there is not some way around this in API mode at least, but it is irrelevant for my current purpose.

What I did was wire pin 6 on the xbee to a digital pin on the Arduino (I used 7) then use a pulse detector to find the period of the wireless signal coming in.

int pin = 7;
unsigned long period;

void setup(){
  Serial.begin(9600); 
  pinMode(pin, INPUT);
  Serial.println("Getting started");
}

void loop(){
  delay(100);
  period = pulseIn(pin, HIGH);
  Serial.println(period);

}


It is not perfect, but for now it works, might help someone else in the future.