Ethernet jitter has nothing to do with DAC jitter. Or should not. The reason is buffers built into the streamers, which may hold several seconds worth of music. The buffer's output is doled out by the DAC chip itself on demand.
Even a loss of network connectivity lasting several seconds should not impact the music, or video for that matter.
Certainly network latency of even hundreds of milliseconds and jitter in the same scale should do nothing to the audio jitter except in poorly designed and tested systems.
