This makes perfect sense then, as I have previously stated, Madara sees himself as the the new Amitabha Buddha, remember when Tobi spoke of Nagato as being the "Third Sage of the Six Paths" implying that the first two are the Rikudou Sennin and Madara (who awakened the Rinnegan) now, both Rikudou Sennin and Madara desired peace, however the former desired true peace while the latter desired an illusory peace in the Mugen Tsukoyomi, this would be antithetic to what the original Amitabha (Rikodou Sennin) wanted, true peace, what Madara wants (The Self-Proclaimed New Amitabha) is an illusory world, or known as Maya in Indian Philosophy, and like in Indian philosophy. True enlightenment is achieved by recognizing the illusory world (Maya) and only from this realization can one truly attain true enlightenment (Nirvana) however Madara (The Self-Proclaimed New Amitabha) desires the former, the Maya (Illusory World) as the absolute truth which is contrary to what the true Amitabha (Rikudou Sennin) desires. From this we can see the messianic delusions of Madara, he sees himself as the new Sage of the Six Paths who wants to bring peace in the world. However this "peace" is nothing more than an illusion (Mugen Tsukoyomi) therefore he is a False Amitabha Buddha.
Now, with regards to "Dharma" it is in a sense similar to the ideal Shinobi, duty, obligation, honor,etc. and only by following the Dharma of the Amitabha (Rikudou Sennin) can one become a Bodhisattva or an "enlightened human" or a true, ideal shinobi, or sage. This could imply both Naruto and Sasuke, the former (Naruto) is already in most respect an ideal Shinobi, while the latter (Sasuke) is still in the path of darkness, I suspect that when Sasuke meets "The One Who Knows Everything" he will be able to become a Bodhisattva (Ideal Shinobi) and join forces with the other Bodhisattva (Naruto) to fight the False Amitabha (Madara) who has acquired the power of "God" (Juubi). Hence in summation this is what the prediction from your dream means:
Madara will successfully become the Jinchuuriki of Juubi (God), posessing the power of the Amitabha Buddha (Rikodou Sennin) and he proclaims himself the savior of the world (False Amitabha) that will bring peace through a false enlightnment (Mugent Tsukoyomi) but will be opposed by two Bodhisattvas (Sasuke and Naruto) whereas Madara (False Amitabha) will boast that he has the power of the Buddha (Rikodou Sennin) and God (Juubi) and only the Amitabha Buddha himself (Rikodou Sennin) can stop him, foreshadowing the possible unification of Naruto and Sasuke (Nirvana) to reawaken the power of the true Amitabha Buddha (Rikodou Sennin) to defeat the Jinchuuriki Madara (False Amitabha with the power of God/Juubi).
