I know the website has been changing the rules about calculating match scores, and I'm not sure that is all settled yet. (Pretty sure it isn't settled yet.) api.chess.com does have to match the website for this one I think or it's a bug. 
Bug in Team Match score
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@Tricky_Dicky I think that it was a problem related to wrong invalidation of cache because now the two scores are the same.
The current score on the web page is different to the API probably due to different strategy on closed accounts.
example
https://www.chess.com/club/matches/791448 score is 337.5 v 323.5
https://api.chess.com/pub/match/791448 score is 314 v 307