Given two functions:
f(n)=O(log2n) and g(n)=O(log10n)
Does one of these dominate the other?
No.
The difference between bases is a difference by a constant, and constants are not considered in asymptotic efficiency.
In this case, f(n) = O(g(n)) = O(lg(n))
In fact, f(n) = Θ(g(n)) = Θ(lg(n))