The potential for damage depends up the dilution rate and the care taken before, during, and after the job.

If the plants are misted beforehand, and then rinsed carefully right afterwards, you shouldn't experience much of a problem. That's assuming that the workers weren't negligent or careless in their mixing or application.

Pressure washing (with the right equipment) shouldn't flood the soil with a bleach solution, hopefully.

I have had my house pressure washed with bleach several times. The only damage I ever sustained was a bit of spotting on evergreens that were right up against the house. Rhizo's idea of rinsing the plants is an excellent one. I will remember it for next time. Follow it and you should be fine.

Another point to consider is damage that might be done internally to any plants when using bleach so consider the soil moisture level when the pressure washing is done. The drier the soil, the more likely that the bleach may do damage internally to the plant if it is absorbed into the root system. The wetter the soil, the less likely any damage will be done since the bleach can be diluted by the soil moisture before any may be taken up by the plant.

I have had a professional (Belle Mead Painting and Power Washing co.) "soft" power wash our deck every other year. They have an enclosed trailer with multiple 2-300 gallon containers of water and bleach. He has several power buttons on his "power" handle. He gives all a quick water-only spray to begin, then moves to the bleach/water mix (he controls it) and cleans our flooring and the white railings, they look bright white, like new when he is finished. And, fyi, his final rinse is all water again. I have lots of different types of shrubbery around the decking, he has told me again and again, it will not harm. He is right, in the past 6 yrs (just had it done a month ago) the job is very well done, and it has never harmed any of our plantings! Get a pro!