Heat oil in a large Dutch oven over medium heat. Remove casings from sausage. Add sausage to pan; cook 4 minutes, stirring to crumble. Add garlic and jalapeño; cook 1 minute, stirring frequently. Add wine; cook 2 minutes or until liquid almost evaporates, scraping pan to loosen browned bits. Stir in tomato, oregano, 1 tablespoon basil, salt, and black pepper; bring mixture to a simmer. Cover and cook 10 minutes, stirring occasionally. Stir in corn; cover and cook 2 minutes.
Increase heat to medium-high; stir in clams. Cover and cook 5 minutes or until clams open; discard any unopened shells. Divide mixture evenly among 4 bowls; sprinkle with remaining 1 tablespoon basil.