After searching about the health insurance treatment on 1120S. Here is the update:

S-corp owners' health insurance is actually deducted at entity level. Even though wages expense and health insurance expense are two separated items, but they are combined together on line 7 at deductions section on 1120S return. Obviously it is not easy to identify that health insurance is deducted on 1120S return. 

Even though health insurance expense is deducted at entity level but it is actually reported at line 10(a) on 1040.

Conclusion:   Health insurance is treated as business deduction for both  LLC and S Corp