Before you make any plans to use public transportation to attend a Patriot Center event, be sure to check the times that trains or buses stop running for your return trip, as it is possible that a given show might end after the last run. There is no public transportation that departs directly from Patriot Center after any event.
Here is an excerpt from the Patriot Center website which seems to corroborate your thinking you will need to cab back to the metro:
Patriot Center is indirectly accessible through public transportation. Take Metro?s Orange Line train to the Vienna Station. From there you have a few options:
You can take the CUE bus from the station to George Mason University. The CUE bus stop is on the opposite side of campus from Patriot Center, but it is a quick 5-10 minute walk across campus following the signs to Patriot Center. Please visit the CUE Bus web site at:
www.ci.fairfax.va.us/Services/CueBus/CueBus.htmLastly you can always take a cab from the Vienna Station to Patriot Center. This is probably the costliest option, but possibly the quickest. It is easy to find a cab at the metro station to get to Patriot Center, but you will have to make arrangements for the return trip. There are not cabs waiting outside our venue when a show ends to bring patrons back to the metro station.