Sometimes honey and hot water develops a bit of a foam because of proteins and other compounds in it. So does unfiltered apple juice, due to suspended materials like tannins and pectin.
Doesn't look like an infection to me. Just bubbles. I don't think the time frame you mentioned would be long enough for any sort of funk to visibly take hold, and I don't think the likelihood of infection is very high after using sulphites in your must.