Asking for the luggage to be held at PHX is a bad idea. There is no room out there and the bag will simply be lost. That is particularly true for a carrier which has no US flights, e.g., all of its baggage services are on the sterile side of CBP and a contractor is not likely to hold the bag for more than a few hours.
If you are checking out of a hotel, better to make arrangements with the property to hold your bag should it arrive while you are in California.
Alternatively, just update WorldTracer to have the bag sent back home.