Yes, Panorama can be done in twin pregnancies, as well as pregnancies conceived with an egg donor or surrogate pregnancies.  Panorama can NOT be done in higher order multiple pregnancies (e.g. triplets, quadruplets, etc.) and can NOT be done in twin pregnancies conceived by an egg donor or surrogate.  Some conditions may not be able to be screened for in twin pregnancies (e.g. triploidy, monosomy X, some microdeletion syndromes).