Ibiza's tiny airport was never built with transatlantic dreams in mind, which is exactly why the routing matters more than the destination once you're seated up front. There is no nonstop option for business class from Austin to Ibiza, so the itinerary lives and dies by its connection—and after dozens of iterations on this exact corridor, I've settled on Madrid via Iberia as the most civilized path. Iberia's A330neo business class, with its direct-aisle-access staggered seats, now serves several Austin–Madrid rotations and dovetails neatly with short IB or Vueling hops to IBZ. British Airways routes through London instead, putting you in their Club Suite—a legitimate flat-bed with a door, one of the better hard products in transatlantic business—before a Heathrow-to-Ibiza connection that only really makes sense in peak summer when BA adds frequency. Lufthansa's Frankfurt option is the wildcard: their Allegris cabin is rolling out gradually, so you'll want to check aircraft type before booking, as not every Frankfurt-bound 787 or A350 has it yet.
The insider move here is timing your connection city to the season. Madrid in shoulder months (April, May, September, October) is genuinely pleasant for a 2-3 hour layover with a proper sit-down meal at one of the Iberia lounges near Terminal 4S, while Frankfurt and Heathrow in high summer turn chaotic with holiday traffic funneling toward the Balearics. I've found that flying into Madrid a day early and taking the short IBZ hop the following morning, rather than same-day connecting, saves considerable stress during the July-August crush when Ibiza's single runway creates real delays.
Fares on this Austin–Ibiza corridor swing dramatically based on which European gateway is discounting that month, and the difference between a Madrid routing and a Frankfurt one can be substantial even in the same week. Given how much variability exists across three carriers and three hub cities, setting up fare alerts for this specific route is the smartest way to catch the shoulder-season windows before they close.