I would not use regular Marine Cetol on your beautiful new teak.
Not sure if this is the "holy grail" but since your teak is already perfect, you might consider adding about 4 coats of either Cetol Gloss (preferred), and/or Cetol Natural Teak (2nd choice), or apply the natural, then a couple of top coats of gloss. Both will give you a good result without any of the orange-ness of the tinted cetol products. The gloss is harder than the other products and seems to hold up better and the wood looks natural.
As others have noted, maintenance frequency is subject to locale and use but at worst should be no more than a quick scuff and a couple of maintenance coats, as long as you dont let it get bad and peel.
If you do a search on this site, you'll find lots of discussions on this topic. Some love varnish, some hate Cetol products because of the tint. But the bottom line is with the teak, your results will directly coincide with the amount of effort and time and patience put into it.