Not an expert. My AARP resources say the premiums must be paid by the taxpayer/spouse, so paying it from a personal checking account would make that more clear if it were ever questioned.
There are a lot of other things about SEHI to note. There is a circularity with ACA PTC that is tricky. You can't double dip among SEHI, Schedule A Medical, and Schedule C business expenses. The AARP resource suggests a Schedule A Medical deduction might result in lower taxes if TP itemizes.