State law governs.
There is nothing wrong with a non-profit's applying for grants or soliciting support before the IRS rules, so long as the interim status is disclosed. For a private foundation, the risk is greater, since that type of entity may not grant funds to other than a recognized exempt organization. In the latter case, fledgling non-profits use the offer of a grant, conditioned on IRS approval, as a way to expedite the approval process. In the former case, the non-profit may agree to return the contribution if tax exempt status is denied. And, you have to acknowledge those donations and tell the donor that you have state approval while federal application is in progress.