You should be able to create multiple pointers (CNAME) but you've left out the "IN" part of the record (assuming you're using BIND).
You also want to end the records with dot to show nothing should be appended to the name.
ntp IN CNAME roma.domain.tld.
ntp IN CNAME aladdin.domain.tld.
ntp IN CNAME pages.domain.tld.
What you probably need is to do an rrset-order for ntp records. I haven't done that but discussion here talks about them: