If you want a HRM which supports both bluetooth (e.g. connect all your ANT+ devices to your iPhone) and ANT+ checkout Viiiiva. I got one to replace my flakey garmin premium strap. Sometimes I use my iPhone with my garmin ant+ footpod which is pretty cool.
They are also software updatable now as well - I suspect to future proof them to perhaps support android devices when the rumored android 4.3 update with native bluetooth support is released. Also received an email today to confirm my shipping address. They are sending out updated HRMs to owners of the original release which can't be updated Looks like I might be able to move to the dark side soon and get an android phone.