Multiple Bluetooth Smart sensors for bike?
Android can just about handle multiple BTLE sensors simultaneously but there are still some low level Android bugs that make it rather unreliable.  The coding for is also a good bit more complex to get working than the single sensor case.  I have support in my app IpBike via a beta version of IpSensorMan

At this point in time if you were getting new then an ANT+ based setup is the preferred route.  But if your looking to work with your current phone which is not ANT capable then you would need an ANT USB stick and things get messy.