Does Bluetooth interfere with WiFi?
Yes, WiFi and Bluetooth can disturb each other.

But both are equipped to handle that. A standard that is not capable to handle disturbance and/or interference will simply be unusable under many circumstances.

The 2.5 GHz ISM band is also used by Microwave ovens and other wireless standards like Zigbee.

Wifi transceivers are able to detect when certain data has been lost and can ask for a re transmission. It is also possible to lower the datarate which makes the link more "robust" in the sense that it is less sensitive to disturbances.

Bluetooth uses frequency hopping, it changes channel (frequency) 1600 times per second. That way if one channel is disturbed only part of the data is lost. Also a re-transmit of data is possible.

So yes, interference happens, it is a fact that the standards simply have to deal with.