Vinsmock...I'm eagerly anticipating the MS translation of the name as those of MR/MP aren't really that trustworthy regarding names. Vin would make sense though as "vin" is French for "wine", which both fits his cooking theme as the fact that Sanji's nationality in the real world would be French. Not really sure what "smock" is supposed to be. After some searching apparently it can refer in French, Dutch and English to stitching techniques.
Another possibility is that it refers to a smoking or a suit, the outfit Sanji is always wearing and/or to the fact that he smokes a lot. I'm assuming that Sanji's family has similar characteristics to Sanji, which would make sense for this marriage. Big Mum is addicted to food, so it would be rather logical that she would marry someone of her own family to someone of a family that's in the cooking business. So maybe the Vinsmocks are an elite family of cooks?