Porcelain brush pen does not stick to ceramic ring
From the "usage" section of the pen website (my emphasis):


  Daily cleaning: avoid friction, rubbing and scrubbing by positioning the item in the dishwasher so that it is not in contact with other items of crockery or cutlery


These pens are listed as decorative. You are not going to get a permanent bond that is as strong as the original ceramic finish. I am sure if you were to paint and fire the decorations, and then set them on display where they cannot be rubbed or scraped against things, the paint will hold up fine. 

If you wanted to get a permanent finish as durable as the original material you would have to reglaze the item using porcelain glaze and a kiln capable of extremely high temperatures, between 2381℉ and 2455℉ (1305℃ and 1346℃).

(source)