Your assumption is incorrect - Probe requests do not contain the MAC of the AP, only the SSID. Wifi clients usually only save the name and security type/PSK of previously joined networks. In many situations, the same SSID is broadcast by multiple different APs with different MAC addresses in the same area so it wouldn't make sense to remember a specific SSID/MAC pair.

If the same client (iPhone) probes for a list of SSIDs with one random MAC and then probes for the same list again a short while later with a different randomised MAC, you could still track that individual based on the list of networks they probe for.

If the client MAC is randomised for every single new 802.11 probe that makes it harder but you could still track based on a single unique SSID probed for (i.e. something more unique than NETGEAR).

I'm going to look into this and possibly update my tool iSniff GPS.