The Tamagotchi-iD does not have Bluetooth capabilities.
The most common solution to this problem is to purchase a compatible phone on e-bay. Some members have reported success with used phones they've purchased for a low as $10. (I purchased my Treo 600 for about $20.)
All versions of Tamagotchi use Infrared. None use Bluetooth so far, though. But it would be nice because now, most devices use Bluetooth, and most things like laptops, computers come with Bluetooth. My computer still uses Infrared because it's an old comuter made in 2000.