Given the US bias of HBT, I suspect not many will have had Atlantean, and
their website isn't exactly helpful. Reading
the reviews you get notes like "orange, nectarine and grapefruit", "grapefruit, pineapple, leamon and mango", "orange, very slight pineapple and melon", "Lemon, herbal, strong apricot, lots of grapefruit juice, bit of pine", "melon, peach, tangerine".
The obvious thing to do is just drop White Hag a line and ask them - often breweries will be happy to at least give some pointers on stuff like what hops they use. But Amarillo and Citra are obvious places to start.
As for a recipe, try
Braufessor's as a starting point, aim for about 1.055 OG. The fact that there's not too many mentions of peach makes me think they're not using a Conan derivative so use Wyeast 1318 in the first instance unless you know anything about what they use as a house yeast.