The answer to your question is No, and sort of yes. The PWD is a very high performance DAC. For a few years I have been using a dedicated Music Server PC as my digital "Transport" and controlling the PC with some type of handheld computing device running VNC. With this type of setup the Music Server PC must be within a few feet of the DAC. In addition getting a quality digital signal from the PC to the DAC is problematic. There are only a few PC Cards that provide a really high quality digital output (AES/EBU or SPDIF - Lynx or M-Audio). USB, even with the latest FOTM asynchronous DAC's doesn't offer the performance of the best AES/EBU or SPDIF connections into a quality DAC (It's the reason Asynchronous DAC's usually don't offer AES/EBU or SPDIF connections; it would encourage comparisons). I disagree adamantly with PS Audio's claim that the USB is #2 (Behind their I-2S) digital input. I feel that this listing is them bending to market pressure (The Market wants USB to be the High Quality Input).
What the Network Bridge is (I believe this is what you are referring to with PWB) is a plug in interface that allows Streaming the digital signal (Music) from a Network attached UPnP device (Either a NAS or as in my case a PC attached to my network) to the PWD (The DAC) with quality that matches the finest direct connections (AES/EBU, SPDIF, or PS Audio's proprietary I-2S on HDMI cable). The Network Bridge is much more than a simple Network connection, it Buffers and then Re-Clocks the streamed data and then outputs it as I-2S to the PWD. It basically gets the audibly and electrically noisy computer out of the listening room, while still allowing performance as if the computer was right there using a Lynx or M-Audio sound card as its digital connection. The iPad interface is hardly perfect, but it is usable, and it is ever improving.