I have updated my iPhone 6 Plus to 8.1 today and have Yosemite on my 2014 rMBP 15.4". I can connect my iPad to the rMBP but still have problems with the iPhone 6 connecting. Any suggestions?
power off and then power on everything.
sign out of icloud on everything
power off and then power on everything
sign into icloud on everything
power off and then power on everything.
the above concept works 90% of the time on 90% of every computing thingamajig on earth
the other 9% of the time you need to clean the connections
the remaining 1% of the time is actual issue