It’s the busy season for Boston-based party plannerBryan Rafanelli, who hosted a weekend fund-raiser in Provincetown for VP Joe Biden before flying to Tampa for the Republican National Convention. (Guests at the Biden bash, held at the Pilgrim Monument, included state Representative Sarah Peake, state Senator Dan Wolf, congresswoman Niki Tsongas, and “Angels in America’’ playwright Tony Kushner.) So what’s the guy who handles arrangements for Obama’s White House state dinners — not to mention Chelsea Clinton’s wedding — doing at the RNC? He’s helping Huffington Post founder Arianna Huffington with Oasis, described on the HuffPo website as a “wellness-focused destination’’ at the Republican and Democratic conventions, a lounge-like “mini-retreat offering healthy snacks, spa sessions and yoga classes’’ to conventioneers. We’re told Rafanelli and Huffington only recently became friendly, having met at the wedding in June of Facebook cofounder Chris Hughes and Sean Eldridge.