Bone Tempering brings forth Divine Skills, Vein Condensation connects heaven and earth; Wei Mo stepped into the Vein Condensation stage, making his cultivation base an entire grand level above Pang Feng. Vein Condensation and Bone Tempering are as different as Tianqian.
Once one's cultivation reached Vein Condensation, they could connect with heaven and earth; this difference is that between the acquired and the innate.
Bone Tempering is still in the realm of the acquired, but Vein Condensation, which connects heaven and earth, signifies the transition from acquired to innate. Only by achieving an innate body can one lay the Foundation of the Great Cultivation Path.
The disparity in realms between Wei Mo and Pang Feng almost guaranteed Wei Mo an unbeatable position. Pang Feng's "Ground Collapse," which combined "Cloud Character Thirteen Breaks" and "Eightfold Strength," was immensely powerful; had Wei Mo not stepped into Vein Condensation, he would have surely been defeated.