Arduino- bluetooth - Android - Html/php

Hey guys. Got some idea's for a project and wanted to know if this is doable or if anyone has any advice.

I want an arduino equipped with some sensors, a bluetooth module and an led to send the sensor data to an android (or iphone if its possible) phone via a bluetooth connection. I then want an android app to post that data to either a php server or html page. I also want that app to be reading sensor data from another php / html page and relay the data back to the arduino over bluetooth to affect the output of an LED.

I have no experience with android or iphone apps which is why im a bit clueless. I have found this site
http://www.amarino-toolkit.net/
But i just dont know if an android app can do the things i ask of it. Any wisdom on the topic will be most useful.
Also i have heard that you cannot pair an arduino to an iphone using bluetooth and wish to know if this is true.

This post may help you something.

ArduinoCommander app works via bluetooth using Firmata protocol.
https://market.android.com/details?id=name.antonsmirnov.android.arduinocommander