Hi
@edz and welcome to the forum
There are a few options for getting the BG data to your watch. As mentioned above juggluco, also Gluroo and also G-Watch. Each of these gives you slightly different info on your watch but I'm sure all of them require your phone to talk to the sensor and then it can be shared with your watch automatically. Hence your phone must be close by.
Your phone alarms should be echoed on your watch, but I have missed some alarms on my watch (because a single beep & vibrate could be anything!) until I switched to Gluroo (though I was using G-Watch for a while previous to that).
When in church I have my phone on silent and no vibration and my watch on just vibrate. Gluroo gives persistent vibration (and increasing sound if sound is on) ... It does get my attention if there is any alarm
🙂