Infrared is point to point but Bluetooth is one to multiple point technology. For wifi technically there is no limit for the clients but effective limit (optimum) is 15 clients.
Infrared is narrow angle 30°. So Bluetooth does not need any adjustment. It is enough be in the radius of 10m of the source. Wifi is also like Bluetooth but the distance is 100m.
Infrared cam work between 0-1 m. Bluetooth can work between 10cm to 10m. Even at lab conditions if has seen that it can transmit up to 100m. For Wimax the distance is 35miles (55km).
Fast infrared may let you transfer up to 4mbit/sec on the other hand Bluetooth can transfer at 1mbit/sec speed. Data transfer speed for wifi is 11mbit/sec.
