Greywing and clearwing are both dominant to dilute. If a bird had genes for greywing (or clearwing) and dilute it would be a greywing (or clearwing) split for dilute.
This works the same way as normal and greywing. A bird can't show both mutations it would be normal split greywing
Greywing and clearwing are co-dominant to each other so if a bird had both of these mutations they would both show. The name for a composite greywing and clearwing is "Full body greywing"