As far as these two questions, The delay depends on the exact set up. Since that is a battery powered device, it has to send a message to the hub and then the hub Will send a message to the bulb. Typical delay could be anywhere from half a second to two seconds, but it really just depends on the exact layout of your network.
The geolocation trigger question is another one that varies a great deal from person to person. For some people, phone presence works very well. For others, it has a lot of issues. Also, if you are not in a region which is specifically supported by smartthings, Geolocation triggers may not work at all. It’s one of those “try it and see“ questions. If it works, great. If it doesn’t, there are a number of other alternatives you can try. See the FAQ: