Question: Does it matter what kind of tea i use to grow kombucha?

The brand of tea isn't important, but Kombucha is nearly always made using one of the many kinds of teas or blends derived from camellia sinensis: tea leaves. The black, fermented version is what we're all familiar with in lipton. Assam, Oolong, Darjeeling, etc refer to origins of tea, or tea blends, but they're all the same plant with some differences in terroir and perparation. White and green teas are also made with camellia sinensis (the differences between the three have to do with when the leaves are picked and how they are perpared) though they may be less productive during the fermentation process. Infusions (what we think of as fruit or herbal teas: anything made with something OTHER than camellia sinensis, won't work, unless, perhaps, you are interested in introducing some of the chemical properties of the tea with alternative ingredients.

If you're making Kombucha to drink, it might help to keep in mind that the tea you start with is food for the colony of bacteria that is performing the fermentation, and the kombucha is the product of that fermentation. The acidic content in the tea can help to keep other bacteria from entering the mix, while the stuff living in the SCOBY are especially good at consuming nutrients in the tea/sugar brew.

Obviously, once the kombucha reaches a certain PH or the bacteria are exhausted, or switched off with heat or cooling, the process will stop and there will still be unconsumed tea in the mix. This can be diluted with other teas or juices for consumption.

I heard from Oliver that "the more acidic the tea, the better" -- and that the lowest cost teas like Lipton that are available at any bodega and are so acidic they stain ceramic mugs and teeth (!) actually work great.