Hi is there an office of China unicom in Kunming or can I purchase prepaid internet cards for laptop and IPhone from china unicom anywhere in Kunming?

Walk down any street. About every third shop will be a phone shop of some kind.

Download the China Unicom iPhone app here: 中国联通手机营业厅客户端(官方版) by 中国联合网络通信有限公司
appsto.re/us/olQ0y.i —- FYI, it's all in Chinese, but if you can figure it out, you can change your plan and add data for really cheap at any time. It's been a lifesaver to me! No more going into a shop to switch something around.

Without a Chinese ID most shops will not give you any SIM cards. Only the official retailers, a few scattered around town, can issue SIM cards providing your passport.

The main China Unicom office is on the Panlong River, I think just south of the Renmin Lu / Qingnian Lu intersection. If you take a passport they can sort you out. However, beware their coverage in rural China is generally worse than China Mobile... you will only get fast speeds in major towns, but their speeds are good and costs not bad. Also beware their dongle driver software on Mac, make sure you get a new dongle (non-Huawei, or Huawei 2015 or later) as the old ones from Huawei replace critical libraries on OSX systems and cause no end of problems.

Has the main China Unicom shop changed location in Kunming?

Still there ricsnap, from 9am - 19pm, on the small street just west of panlong river on 金牛街