The Pro Imaging Bill of Rights is designed to protect photographers from unscrupulous competition sponsors/companies effectively ripping off the photography and his(or her) rights to own and use their own images exclusively.
This competition is not limited its usage to promoting the competition, and instead states that it shall have the right to use any submissions for marketing purposes and for an unlimited period of time.
As a photographer, it is you who ultimately have to weigh up whether or not you wish to enter. You should consider whether you are happy for them to have free unlimited rights to use your entry (it might be fine if you win) for any purposes they so wish.
You should perhaps also consider whether you are likely every to make an income from the entry you submit. I would certainly be unhappy if one of my own stock images was used in this way, which is why I protect them, however if I had taken an image especially for this competition, then where is my commercial loss?
So perhaps, if you class yourself as an amateur, have taken your photo especially for the competition, and have no intention of adding your own images to a library or promoting them in any other way - then maybe the Bill of Rights will not matter to you.