If the channels are free (no other device is active), WiFi (WLAN) is the fastest wireless transport of data (afaik). For a real-time transfer as You planned, you may use UDP and transfer data direct via a socket.
But check the maximum speed by studying WLAN. Have a look to the bandwidth, and then decide for the scanning cycle of your analogue input. For the data use integer values organized in octets (bytes).
It also depends on the implementation of the socket at Your MC. A socket may have a internal delay, waiting for another sending request and collecting small data packets.
If you scan 12,5 Msps with 12 Bits each sample and code it to 2 octets (16 bit), you need a bandwidth of 12,5 * 16 = 200 MBit/s payload.
My experiences with WLAN and UDP via direct socket access are with speed less than 100 messages per second (broadcasting sensor data), which is very slow compared to Your application. And I do not expect to pass real time data through a system with many active devices with higher speed.