Dear Girish, Rhizopogpn has been extensively studied experimentally, physiologically, taxonmically, and phylogenetically. We can say with high confidence that it forms mycorrhizae only with the Pinaceae and the Arbutoideae, a small group within the Ericaceae. However, Australasia has numerous Rhizopogpn lookalikes in the Boletaceae associated with Eucalyptus and other Myrtaceae, I suspect several to many of these might occur with dipterocarps as well. If you find any such specimens, I will be happy to work with you on their taxonomy.
I have collected one species just like Rhizopogon from Dipterocarpus forest, identification work is still under progress, I shall inform you whenever I confirm it as a species of Rhizopogon. But most probably, it is a member of Sclerodermataceae.