I presume those measurements are in centimeters? If so, an individual yemen chameleon should be moved into its own a much bigger enclosure from about 4-6 months.
However, I would separate those chams as soon as possible. Some people allow chams to live together until they're a little older (i.e. 4-6 months) - after that, they will not tolerate living together in an enclosure, regardless of what sex they are. Worst case scenario is that they fight with one another and severely injure/kill one another. Best case scenario is that one cham dominates the other cham physically, and the subordinate cham eventually dies of stress related problems.
That's the reason I wouldn't keep them together even when they are young. In such a small enclosure they're going to be competing against one another for heat, light, water and food. One of them will invariably lose out to the other, which would be detrimental to its long-term development.
What sex are your two chams?
You said the cage came with a ReptiGlo 2.0 - that's the wrong bulb. You need a ReptiGlo 5.0 - the 2.0 doesn't put out enough UVB for chams.
It would also help if you got live plants. Veileds only start eating the plants in their cage when they're about 5-6 months old (at which point you should definitely have live plants), but even now, live plants will be beneficial at keeping the humidity up in your cage.
You would probably do well to get yourself a digital thermometer and hygrometer so that you can properly monitor the conditions inside the cage (especially important that you monitor the temperature at the basking spot/s and make sure it's not too hot for your young chams).
Finally, I don't know how any pet store can sell two chameleons and call it a 'starter kit'. Firstly, it's difficult enough to keep one cham healthy - two chams are certainly not for beginners. Secondly, by buying two chams you are committing to eventually having to keep two separate enclosures, which ultimately doubles the cost of everything - I would think a 'starter kit' should be designed to keep the costs of entry into the hobby down. Just my 2 cents.