There is not much on the genetics of daylilies, even of diploid daylilies, because geneticists have had difficulties in producing the standard crosses using the standard techniques for the scientifically accepted analyses.
Dominant and recessive always need to be described in reference to something. In other words dominant to "what" or recessive to "what". For example, some flower colour might be recessive to purple but dominant to cream.
Tetraploid genetics are usually much more complicated than diploid genetics.
Basically, my opinions.
A watermarked plant crossed to a very light coloured flower may produce some watermarks. When crossed with dark flowered plants it would be less likely to do so. When crossed with dark flowered plants it will depend on whether the dark-flowered plant is itself from crosses of dark-flowered parents or from dark x light flowered parents.
The eye zone is probably present in all or nearly all daylilies. It cannot be seen with the naked eye in daylilies that do not produce easily visible amounts of anthocyanin pigments in their flowers. However, when such flowers are looked at under UV light or with various chemical procedures the less obvious pigments become visible and the eye zone is displayed.
My guess is that watermarks and eyes are more or less the same. There are probably many genes involved that determine how much pigment is present in the eye zone area and how much pigment is present in the outer areas. Higher amounts of pigment in the eye zone area and lower amounts in the outer area produce an eye. Lower amounts of pigment in the eye zone area and higher amounts of pigment in the outer area produce a watermark. All those amounts will probably vary continuously. There is probably a simpler genetic basis to the presence versus absence of the strongly coloured anthocyanin pigments delphinidin and cyanidin versus the lighter cream, light yellow pigments that are their precursors (the compounds that are produced first and then modified to become cyanidin or delphinidin, etc.)
