This may work for you.
Turn your wireless into an AP for other devices. Set-up a wifi network for the Cell to connect to, and then its already coming to your PC rather than to the router first.
routing to your pc isnt the problem, its through that is. Because your PC is "switched" you have to do something to it that will allow "promiscuous mode" to work.
Promiscuous Mode for the ethernet (or wifi) requires shared bandwidth via hub, not switched bandwidth. In switched bandwidth the only traffic that comes to your machine is that which the switch knows is associated to your machine (nic's) MAC Address, only when a packet comes to a switch, and the mac is unknown, will the switch broadcast that packet to all ports.
In a shared network with hub, traffic heard on 1 port is broadcast to all ports, thus if the PC's nic is in promiscuous mode, it would hear everything.
Other items .. the above link to an app that is basically enabling Routing & Switching on your PC. If you dig, you may find ways to enable it without the app, give your nic a second IP address (static ip addressing) and if so, could give your PC's new IP as the "gateway" for your phone. either way traffic needs to flow through your PC so that the Nic listened to in Wireshark, is hearing the traffic passing though.