Capturing WLAN traffic on Windows depends on WinPcap and on the underlying network adapters and drivers. Promiscuous mode (mode in which you can see other machine's traffic) can be set; unfortunately, it's often crippled. In this mode many drivers don't supply packets at all, or don't supply packets sent by the host.
Even if promiscuous mode works with your WiFi adapter and drivers, you can only do that on an unprotected network. On a "protected" network, packets from or to other hosts will not be able to be decrypted by the adapter, and will not be captured, so that promiscuous mode works the same as non-promiscuous mode.