Will ipad wifi signal interfere with bluetooth itself or nearby ipad devices?
Do you mean its own bluetooth radio?
Your question is ambiguous.
Normally BT does not interfere much with surrounding Wi-Fi devices, or vice-versa. Newer BT radios have ways of not using channels that it sees are already in use.
However I would not try to use both in the same device simultaneously, for several reasons. Some manufacturers have tried to use both simultaneously, and gave up after their prototypes didn't work very well. You'll sometimes find both radios in early model devices labelled as only one or the other- not usually in really small handheld items though.
A class II BT device can easily reach out to 350' with a good antenna. Thats much higher than the expected 10 meters. What symptoms are you having?