Yes, you did overlook something.

Bus routes 208 and up are operated by Pace, not the CTA. Pace does not accept CTA 1-, 3-, and 7-day passes, so you were charged the single ride fares.

Pace does accept the 30-day pass and the CTA/Pace 7-day pass which costs $5 more than the CTA-only 7-day pass. Pace also accepts transfers to and from the CTA when paying the single-ride CTA or Pace fares from a Ventra account.