@Izkata makes a very good point: the two snippets express different ideas, even if the end result is the same. The appropriate comparison would be against phoneNumber = isApplicationInProduction(headers) ? headers.resourceId : DEV_PHONE_NUMBER.
Apparently chat doesn't like newlines… I just wanted to say that for this specific case @JimmyJames also makes a good point. A good way to resolve this sort of Dev/Testing/Production difference is to pass in a configuration of some sort.
I would worry about trying to trace the hell of single line functions calling single line functions, ad infinitum. In days gone by functions could potentially have major performance hits (eg, using CICS Cobol, which ran in 2k blocks, where performing a function meant dropping 1 block from memory and loading another, then back again).