Yes, it is possible - however, a quick experiment shows that it's a little tricky and that the results aren't as good as what you can from a bigger camera.

The bokeh discs are just out of focus lights - so all you have to do is place some lights and "defocus" them.

Here's what you do:

1. You need an iPhone 3GS or later, earlier models are not capable of changing focus and so can't make anything out-of-focus.

2. You need lights, Christmas lights often used for this, you need to place the lights as far away from you as possible (the farther away they are the bigger the bokeh disc) and you need them to be much brighter than the background (that last part is easy, just make sure the background isn't acting like a big reflector directing light into the camera and you'll be fine).

3. You need to focus on an object that is very close to the phone, something like 5-10cm (2-4inch) from the phone, maybe even closer - anything farther and the lights will be in focus - this means your subject has to be quite small to be this close and still not fill the frame (just place your subject in front of the phone and tap on it on the screen to make the phone focus on it)

This will be easier if you can use something to hold the phone (and the subject) since any movement will make the phone refocus and bring the lights back into focus.