They really are two different approaches. And it may be that if we are successful with this bill, we won't need an environmental bill of rights.
An environmental bill of rights comes from the ground up, essentially, literally. It starts with people and it's a legalistic process based on a kind of rights-based notion of when things are violated, you have the right to ask for clean air or clean water, or whatever else. It's a different kind of mechanism.
If you're driving the process from the top and empowering governments or commanding governments to have policies that are in line with sustainable development, and having those policies reported on and then audited every three years, you may not need to have a bill of rights as well. You could go one way or the other, but I'm not sure you would need to go both ways.