Virgin Australia Velocity - Carry-On baggage limit on Virgin Austrlia on a V Australia ticket

Greetings everyone:

I have a question, if I am traveling on a V Australia itinerary from SFO <-> LAX via Delta Connection, LAX <-> SYD on V Australia and then SYD <-> MEL via Virgin Australia, which policy is in effect for the carry-on luggage since it is one ticket? When I talk to V Australia, they tell me that the carry-on is based on the V Australia one piece 15lb/7kg 115cm/45" limit for all three flights which I can see would work for the Delta and the V Australia flight as those are both 45" limit but I noticed on Virgin Australia, it has a 105cm or 41" limit for the carry-on? Is V Australia correct that their carry-on allowance applies to Virgin Australia for the Sydney to Melbourne flight? Thanks!

you should get the allowance of V Australia as it is the most significant carrier.

As long as the domestic sector is on the same VA ticket, then the baggage rules from the international sector would apply.

Thanks to both VH-RMD and the Virgin Australia's own representative. For some reason, I thought only the checked rules would apply to the VA, DJ and DL when all flights were on the same ticket but wouldn't DJ for the domestic sector actually use their own measuring device for the 41" maximum for carry-on or do they actually separate the VA ticketed passengers from the non-VA/DJ only ticketed passengers since it seems that would be more hard work. Speaking of which, for the carry-on bag, I'm interested in baggage that costco.com sells and it appears that the dimensions are 45.5", assuming I stay within the 15.4lb limit, would the airline actually allow the bag with the 0.5" over the limit, meaning DL, VA and DJ in this case since the 0.5" is because of the hardware of the baggage.