Suggestion: Offer the same options as in /settings in the property menu with regards to spawning in this property or not. Allow for the spawning in the house only on a city-by-city basis, so that you end up in your house for the active city. This would make houses more valuable to players since the utility of them would be increased.
Example: You could bring up the property menu inside your house in LS and set it as your spawn inside or outside just as you could in settings. There are settings to specifically set it as your LS home so you only spawn in it while LS is active. Then you do the same for your SF / LV homes and so forth.
Example in the UI text: House #1 set as your spawn point in Los Santos. You will now spawn here while the city is active.
In the menu:
LS Home: House #1
SF Home: House #2
LV Home: House #3