Net Limiter will only monitor YOUR computer, it won't monitor the other peoples' machines unless they're using your computer as a gateway (which would make a wireless router kind of pointless).

Your best bet would be to look into whether your router supports SNMP-querying (check the manual, ask the manufacturer/vendor) and, if so, to look at a program like PRTG (a free SNMP-management program, that would let you query your router for whatever information it stores via SNMP).