no. sadly. in V1, a celestial/pegasus could breed with a normal pony IF they were married with a 1% chance to get a celestial/pegasus when breeding.
in V2 this is no longer possible to breed normal race + special race.
when i try to marry one of my special race ponys with a normal race pony, it says:
Breed impossible between these 2 races
even if the pegasus/celestial is female.
HOWEVER, pegasus can breed with celestial and vice-versa.