Toss fennel, celery, celeriac, parsley, celery leaves, and half of pomegranate seeds in a large bowl. Whisk together the shallot, mustard, spice rub and apple vinegar. Slowly drizzle in the lime oil. Toss fennel mixture with the vinaigrette and garnish with the remaining pomegranate seeds and a drizzle of pomegranate vinegar.