Poached Chicken: Combine wine, 1 1/2 cups water, vinegar, garlic, lemongrass, ginger, cinnamon, bay leaves, chile, and salt in a medium pot. Bring to a boil, then reduce heat and simmer until flavors are released, 10 minutes. Add chicken, making sure it's fully submerged in liquid, and simmer, covered, 7 minutes. Remove from heat and let stand, covered, 5 minutes. Use tongs or a slotted spoon to transfer chicken to a cutting board. When cool enough to handle, thinly slice. (Reserve strained broth for another use.)
Lemon Citronette: Whisk together lemon juice and sugar in a bowl. Slowly whisk in oil until combined, then flaxseeds and chili powder. Season with salt.
Serving: Divide endive, watercress, chicory, radish, and chicken evenly among 4 plates. Drizzle citronette over salad; serve immediately.