The link you provided even admitted the Clintons got free publicity and free first class travel and such paid for by the foundation. The Clintons refuse to fly commercial, only private planes, the best hotels, the best food, etc. All paid for by the foundation.
On my own tax forms I had to claim “company perks” as income. Company car, meals, lodging, cellphones, anything provided to me by the company was considered to be a form of pay. Well the Clintons all get tens of millions spent on them by the foundation, so does that not count as income for them too?