We expect that post-singularity there will still be limited resources in the form of available computational resources until heat death.
Those resources do not necessarily need to be allocated fairly. In fact, I would guess that if they were allocated unfairly the most like beneficiaries would be those people that helped contribute to the creation of a friendly AI.
Now for some open questions:
What probability distribution of extra resources do you expect with respect to various possible contributions to the creation of friendly AI?
Would donating to the SIAI suffice for acquiring these extra resources?
You made a certain prediction about the AI's likely behaviour, and you either did or didn't contribute to the AI's creation based on that. However, whether or not it rewards you wont change that prediction, nor will it change whether you're the sort of thing that will act in a certain manner based on that prediction.