Fresh country air, sprawling hillsides, bloody good wine and 14 of your closest friends. Here, unique country houses perfect for group getaways. By Alissa Jenkins and Megan Arkinstall Stonebarn, Quinninup, WA Where: 170 kilometres south-east of Margaret River. What we like: Although this luxury estate has been designed with groups in mind, it functions like a private retreat for couples as well, as every guest suite features a private balcony, kitchenette and en-suite, each with a claw-foot bath and double vanity. (And check out the four-poster king-sized beds!) The shared areas also include a full kitchen, well-stocked wine cellar and...