Rome Toolkit .com diz que não.
What Is Not Covered By Rome Travel Passes
For buses, you can only use the Rome travel passes on the city buses. You cannot use them on the Rome hop on, hop off sightseeing buses or the airport buses to either of Rome's airports. On the trains the entire Metro system is covered and local services in the city of Rome district are also covered. The travel passes do not cover any of the trains to Fiumicino Airport, the main airport for Rome, this includes the Leonardo Express train running non-stop between Fiumicino Airport and Rome's Termini Station. You cannot use the travel passes on the trains to and from Rome's cruise port, Civitavecchia, which is a long way outside Rome.
Mais algumas informações sobre isso de outro fórum de discussão.
The CIS will work on the FR1 (FM1). It is the same price as the 2 zone CIRS. However, the CIS may not be valid all the way to the Airport, in which case you will need the regional pass, a 3-zone CIRS which is 7 euros more.
E .. Para uma confirmação 'oficial'
O site do Roma Pass tem um PDF que mostra que o limite para o trem FR1 é duas estações antes da estação FCO.
CONNECTIONS TO AND FROM AIRPORTS (Leonardo Express train, FR1 train, local urban services) ARE NOT INCLUDED IN THE TWO CARDS. Validity Limit of the Roma Pass.