Yep, I'm having the same issue specifically with iPhone 6 and the BlueBuds. I've found they work fine on iPhone 5S with 8.0.2 and with iPad Air on 8.0.2, but disconnect constantly on iPhone 6 on 8.0 or 8.0.2. I've also found that the iPhone 6 doesn't have any issues disconnecting from other Bluetooth headphones. Something specific with the iPhone 6 and the BlueBuds. I opened up a case with Apple Support and sent some diagnostics to Apple, and they are seeing the Bluetooth stack crash constantly, but we've not yet been able to determine if the issue is software or hardware or related. One thing I've found though is that doing a full Reset of Network Settings from iOS causes the problem to go away, at least for awhile. I'm still troubleshooting and trying to root cause.
I have several other Bluetooth devices around which might be also contributing to issues, such as Tile devices (extremely buggy and a definitely a possible factor), a Fitbit, a Pebble watch, other Bluetooth Mac and iDevices, et cetera. Still removing things and testing.