Connecting an environmental sensor to multiple smart phones
One option is to use one mobile phone as the bluetooth "base", which connects to the sensor modules. This cellphone would also run a web server, such as kWS - Android Web Server, and would be configured as a WiFi hotspot.

The other cellphones would then connect to this hotspot, and access the web server. 

You would need to modify your existing sensor data retrieval application to provide the data suitably formatted to the web server as content.