In an August 18, 2015 Technical Interpretation (2015-0581431E5, Underhill, Cynthia), CRA confirmed that in most cases a deduction for PHSP premiums paid for a sole proprietor (subject to the limitation in Section 20.01) can be made, even if the spouse of that sole proprietor is also a sole proprietor and deducts an amount in respect of premiums for another PHSP that covers the same individuals.
For further information see VTN Monthly Tax Update Seminar, Issue No. 412