How do I delete HomePod settings from my iPhone?

It’s still tied to your Apple ID. In you phone Settings - Your Name at the top, scroll down to your list of devices , tap on the HomePod, scroll to bottom to Remove from Account (in red)

So you’re saying it’s still in the Home App on your phone?

open the Home App and tap on HomePod, then tap the gear icon for settings, scroll to bottom and tap Reset HomePod and choose Remove Accessory

See this article for more information to see where you’re signed in and to Remove: Check your Apple Account device list to find where you’re signed in

You’re welcome :)