Indeed, after joining Sonesta Travel Pass, the first Sonesta Simply Suites I stayed at tried to claim that the Sip 'n Snack credit is only available when you're using points, not on a paid stay.

I wrote to Sonesta Travel Pass about that, and within hours I received a email response explaining that the hotel was wrong, and they issued 1000 bonus points to me as compensation.

By that time I had already checked out of the hotel, because the person checking me in at night had told me to check the next morning about the credit, and it was the person on morning duty that claimed that the credit was available only when you stay on points, and I was only there for one night.