Up to now, using your Microsoft Band with Windows 10 Mobile builds has been pretty much impossible, and that's if you could actually get the Builds installed and working on your Windows Phone.
Build 10136 released today is touted as more of a spit-and-polish for Windows 10 Mobile. It does provide some new features including improvements to Cortana, photo and camera, and one-handed operation, but some additional attention has been made to getting more of what's supposed to work working.
Per Gabe Aul, as part of that spit-and-polish, the MS Health App will work with the Microsoft Band Bluetooth sync.
@Yorkshire_Ale Yep!— Gabriel Aul (@GabeAul) June 16, 2015
So, if you dare load up this latest Build, you can start to see some things you expect to work for the completed release.