My wife has an iPhone, but I have an old iPad hooked to her account. I can see where all the air tags are, and locate them or activate the noise function. For traveling, there's no real benefit to having an iPhone vs an iPad.
The main bonus that the newer IPhones have is the ability to locate them like a homing device. If you're within 30 feet, it will actually tell you which direction and how far away it is. Like a compass, it points you towards the air tag, letting you get to within a foot or so to find it. For locating a lost item at home, it's much easier to use the iPhone.
But for gps tracking, the basic Bluetooth check in network with apple devices gives you the location of all the devices, within a few meters or so.