Asking your interviewer to have the school re-review an application that it previously rejected sounds presumptuous (as it implies that they made a mistake in rejecting your partner's application), unlikely to move the needle in your partner's favor (why would they substitute your request for their judgment?), and thus the request may potentially be harmful to your chances of admission. I could see making such a request if you had more leverage (e.g., you're a Nobel Prize Winner that they would dearly like to add to their faculty and you've made clear that you and your spouse are a package deal), but medical school admissions is a seller's market.