I was having a problem getting my wife's iPhone to work with Siri even though I had no problem getting my iPhone to work.
The Lutron Smart Bridge App worked fine on both iPhones but I wanted to get the Siri Integration to work especially since we both have iWatches.
The problem I believe was with Apple Home Kit syncing with our different iCloud Accounts. Somehow it didn't work using my icloud account and then sharing it with mywife's phone. I had to set it up on my wife's icloud account and then share her icloud account to my Homekit.
In the Apple HomeKit App it would allow me to add an invite of my wife's iCloud account and then the "invite" would appear on her iPhone HomeKit, but it never would complete the invite setup. The apple progress circle would spin and spin but never complete.
I ended up pressing the reset button on the SmartBridge for about 25 seconds (until the light bar around the Bridge flashes). Reinstalled the SmartBridge to my wife's iphone first (had to re-scan the Smart Bridge code on the bottom of the Smart Bridge).
I got everything working on her phone. I deleted the
"MY HOME" on my HomeKit account. I then sent "invite" from her Home Kit Kit to my icloud account. The "Accept Invite" Worked!