This is the very reason I won't get that when my babies go to the vet. Every one of mine who had it in the past have had issues with reverse sneezing afterwards and it never went away. The vet says there is no connection but gee, it's funny that it showed up shortly after the bordatella was included in the routine.
I have learned to groom mine by myself and I don't show, they don't go to doggie day care or ever get boarded so I won't allow the vets to coax me into that part of the vaccination routine. I would rather treat the symptoms then fill their system with something they don't need every 6 months of their lives.
Mine get the required rabies and distemper/parvo and that's it but I will do titers before their next booster is due to see if they eve need it again.
Have you considered or looked into a mobile groomer? The one I talked with here doesn't require bordatella because they only do one dog at a time right at your home so there are no other dogs around.