I have merged the tags. I didn't try to track how many experts in complex variables (whether in one or several variables) weighed in, but to my non-expert eyes the proposal seemed reasonable.
I think they should be merged, as choosing one tag instead of the other seems to convey little information. I think we should also add the expression "complex analysis" in the tag wiki excerpt of cv.complex-variables for clarity so that it would read:
Complex analysis, holomorphic functions, automorphic group actions and forms, pseudoconvexity, complex geometry, analytic spaces, analytic sheaves.