I think Kunminghua is very hard to understand Chinese people from another province need about 5 months to fully understand Kunminghua. My girlfriend is a Kunming'ren, when she talks Kunminghua i only pick up the words like: Shillema, re'endelah, ge shi. The meaning of a sentance is very hard to figure out. Anyway i guess 1 on 1 is easier, but following a bunch of kunming'rens conversation is very tough.
So Kunming locals will rarely talk putonghua in a group.
You can take a bus ( I thought line 1) or taxi (in high season you have to keep in mind to wait for about 30 min in the line). Don't go with the guys who offer you, to bring you to your hotel. They ask for a higher price then a taxi and are not reliable.
You can also check with a local travel agency in Kunming called Wonders Of Yunnan, they have a webpage for airport pick up. They have an English speaking staff, very reasonable priced and work professional.
responding to the message of mamasaidknockout. The overall salary for the chinese teachers is very low. My teacher at mei's mandarin school was begging me to come to school or else she would not even get her salary, because nobody was at that moment in class.
It is sad to say, but i think the low-rate the Chinese teachers get, might be the Chinese standard.