At present, Apple AirPlay supports a maximum sample rate and bit depth of 44.1 kHz/16bit. This is a limitation of Apple's technology that may or may not receive further expansion in the future.
Therefore, Cambridge Audio products that support AirPlay, are limited to this sample rate and bit depth. This means Apple's recent announcement of Loseless Audio is not supported in a loseless format over AirPlay and will be restricted to the above mentioned resolution.
It is to be expected that when streaming from Apple Music, on an iPhone, over AirPlay to a Cambridge Audio network player, the resolution will be 44.1kHz/16bit AAC. When streaming from a Mac (or Windows PC), this will adjust to 44.1kHz/16bit ALAC.