I have used petal cleanse on our rats when we had them a I was so allergic that exposure to rats gave me asthma attacks (I don't suffer from asthma at any other times). I believe it helped a little, but in the case of severe allergies, not enough to make a big difference sadly.
I have had pets since I can remembers (mainly cat's and dogs) as I got into my teens my allergies got worse and worse, and in my 20's I noticed my allergy to rats was most severe, and I had become a lot more allergic to cats too.
I was so happy to find out that I'm not allergic to Deej!
My doctor said my allergies may go away when I'm in my 50's, but sadly even with prescribed meds I can't have rats or cats.
If it is going to be an outdoor bun I don't see any problem, but if it is to be a house bun I'd be concerned (all us house bun owners know what bunny fur is like for getting everywhere).
With our rats I used to have to make sure they all lived in one room that I could close the door on to cut down my symptoms, but it wasn't until they all passed away I realised how much my breathing and eyes and other symptoms had been affecting me.