On second thoughts, it is not so straightforwards as I'd imagined. The question is whether "team" should take a singular ("builds") or plural ("build") verb? British usage favours the plural, whilst, apparently, our ex-colonial relatives (i.e. Americans) favour the singular.
However, in both cases the correct usage is also context dependent. E.g. If the focus of the sentence is on the team as a whole, the singular form is appropriate. Whereas, if the focus is on the members of the team, the plural form should be used.
So, in this case is it the "team" that "builds relationships with businesses..." or the "rockstar specialists" (members of the team) who "build relationships with businesses..."?
Lastly, it boils down to which jars, and which flows. IMHO the plural flows, whilst the singular jars. However, that may be influenced by the fact that I am a Brit. So I'm far from unbiased!