I started from Street when i was young at the year of 1993, after 1 year of Street then i gather my friends to go over into Flatland. At that time i also use my Street bike doing on-land Tail whip then slowly learn Flatland basics like Smoothie/Cyclone/Fire Hydrants and more.
I would say 100% yes, but remember most Street frame have long top tube, so you need some times to get use to it, if you intend to have deeper interest in Flatland then you may consider upgrading your frame into a Flatland type.
Another advice to you guys, in the beginning you may feel Flatland is hard, but you must slowly pick up basic and have faith with yourself. Hopefully you can stay longer in Flatland once you achieve your first Flatland trick.