Rav Berg models himself upon those who preceded him as teachers of the Kabbalah – Rav Ashlag and Rav Brandwein. Rav Yehudah Ashlag was a leading Kabbalist who was active at the start of the 20th century, and is best known for his monumental work, HaSulam, The Ladder, on the Zohar. (This is a Hebrew commentary and explanation of the Aramaic text of the Zohar.)
Ashlag was followed by his prime students who included his sons and Rav Yehuda Tzvi Brandwein. Rav Brandwein was active in Israel, teaching Kabbalah to many different groups of students. One of these groups included Phillip Berg, soon to be Rav Phillip Berg who was to found the Kabbalah Center in the US. (Berg studied in Israel with Brandwein.)
Rav Berg teaches the Kabbalah himself, and heads the Kabbalah Centres around the world where you can learn Kabbalah the way Rav Berg teaches it, and in English.