Are you sure it requires access from the internet to the bridge for V2? I think it may only require that the bridge can access the internet.
I have a V2 with "Out of home control" set to disabled and it works fine with my Echo Dot and with the Amazon Alexa apps on my phone and iPad.
My guess is that the bridge sends status information, including the bridge's IP address, to the Hue site, and the Echo can retrieve that information in order to find the IP address to send commands to.
I have a V2 with "Out of home control" set to disabled and it works fine with my Echo Dot and with the Amazon Alexa apps on my phone and iPad.
My guess is that the bridge sends status information, including the bridge's IP address, to the Hue site, and the Echo can retrieve that information in order to find the IP address to send commands to.