Ahem.

As a TA, I have issued such joint-marketed tickets AC has with other partners. As AC doesn't serve many points in Asia, it requires joint marketing partners to carry its passengers onwards to other destinations, eg BKK, SIN, TPE, MNL, KUL, CGK, DPS to name a few. While it prefers to co-market with *A partners, in many cases, it is not possible as one flight when there are no *A partners flying that route. eg MNL, CGK, DPS, KUL .. so they will market with CX from HKG. When places have more than one airline, eg SIN , any partners may be used when connecting from AC. eg CX or SQ or UA.

So to rest the case.. it is issued as ONE ticket. If the connecting time is legal, it is fine and if AC is delayed, you will be put on next connecting flight.