Bluetooth connectivity

With 2 HomePods, yes. Set up a HomePod stereo pair

Pair two HomePod mini, two HomePod (1st generation) or two HomePod (2nd generation) speakers in the same room to create left and right channels for an immersive soundstage. Creating a HomePod stereo pair requires two of the same model HomePod speakers. You can create a stereo pair when you set up HomePodin the same room as another HomePod or later in the Home app.

Note: When two HomePod speakers are in a stereo pair, only one responds to Siri requests, plays alarms and acts as a speakerphone.

iPhones do not have native support for pairing and playing audio simultaneously on multiple Bluetooth speakers. Apple's iOS devices, including iPhones, generally allow connecting to multiple Bluetooth devices, but only one device can be used for audio output at a time.

Not unless they were designed to operate as a pair.