Based on where and how phonological rules apply, studies in Lexical Phonology (Mohanan 1986; Kiparsky 1985; Pulleyblank 1986; etc.) distinguish between two levels in the phonology; namely, lexical and post-lexical. At the post-lexical level, the various phonological rules normally require particular domains, without which they fail to apply. The question that follows is where and how we define these domains. Considering Akan Noun-Noun and Noun-Adjective phrasal word (compound) constructions in prosodic phonology (Selkirk 1986, Nespor and Vogel 1986 and Hayes 1989; etc.), this paper touches on some aspects of the prosody-syntax interface on the idea that the domain of a post-lexical rule is drawn from the prosodic component, an intermediate phase of interface analysis. The rules that come to bear are tonal (i.e. H-Deletion, H-Insertion and Boundary assimilation) and segmental (i.e. Prefix deletion and Diphthong simplification) ones that apply on the dictates of particular prosodic domain attainment. Thus, this paper argues that the syntactic structure influences these phonological rules, but indirectly through the prosodic structure (Inkelas 1989). Finally, the paper claims that with the prosodic domains occurrences are better defined and accounted for.