My Paddy also has a thing about about bees and wasps - he catches, and is duly stung in the mouth by, three or four a year.
This is not a problem and he recovers from it very quickly - much quicker than I do if stung. It appears to have a very mild irritant affect for around a minute - then it is gone. No pain at all (and Paddy is a major wimp!!)
There is a major danger though - you need to find out from the owners if the bitch has ever been stung before. If she has, what was her reaction? If not then you are right, you should watch her carefully when she is contact with bees or wasps - an allergic reaction can be life threatening especially if the sting is in the mouth or throat.
If no allergic reaction is noted then there really is no reason to try and keep her away from them - you could be encouraging her to hunt them out by your giving her attention when they are around!