How do I know if my IPhone is synced to my watch

javaliga wrote:

...swipe up on the watch and you should see a green phone symbol at the top left corner that means you are paired with the watch.

Clarification: ...paired with the iPhone. And the iPhone is within range of the Watch. When the iPhone is out of range, that’ll change to Wi-Fi indicator or to four dots for cellular. Which radio is in use in the Watch, effectively; Bluetooth, Wi-Fi, or cellular.

javaliga wrote:

...swipe up on the watch and you should see a green phone symbol at the top left corner that means you are paired with the watch.

Never noticed that indication. 😎

Unpair and re-pair it, would be the typical brute-force solution.

Unpair and erase your Apple Watch - Apple Support

Set up your Apple Watch - Apple Support

If your Apple Watch isn't connected or paired with your iPhone - Apple Support may provide some details.

On your iPhone, tap:

Watch > My Watch

The watch you are paired with should be the first item shown. Tap on it to be sure.

Alternatively, when your warts is near your iPhone, swipe up on the watch and you should see a green phone symbol at the top left corner that means you are paired with the watch. See the "Check the connection between your iPhone and Apple Watch\" section n:

About Bluetooth, Wi-Fi, and cellular on your Apple Watch - Apple Support