I LOVE BRIGHWORK!
however, its a real pita
Cover it if you'd like, it will protect it.
No matter what the finish, if left uncovered, you're looking at a year, at best before refinishing. I'm lazy, and I'm cheap.
So, strip the finish, sand away all of it, and teak oil the pajeebers out of it.
Its cheap, east to apply, and when it starts to weather, grab some scouring powder with bleach, nylon brush it, wait for it to dry, and repeat the teak oil routine. The grain will be lovely. (repeat 2-3 times a season, just for fun)