some itineraries on ITA matrix page or google/flights can't work on united.com. 100% UA carriers

if i really have to book those flights on priceline or cheapoair, do i still get the same benefits as on united.com , such as PQM PQD and base miles reward ? am I gonna miss something if not using united.com ?

priceline or cheapoair or expedia show the UA fare class ?