Now that's a good question - from the docs I have it appears that laptops etc using 802.11 which are near the BT devices are more likely to have a problem - for example:

User A ------ 802.11Access Point --------- User B ------ Bluetooth

User A is less likely to be affected than User B. I have no data on what distances make this effect a problem, and as said before, I haven't really noticed any issues I could put down to Bluetooth interference in real life.