Well, the bus ride to Glendale is 2 hours and 40 minutes. The bus ride to OXN is 2 hours and 20 minutes, followed by a 33-minute layover and then a 1 hour 40 minute train ride. So the ride to Oxnard isn't saving much time!
However, note that you cannot book the bus directly to GDL unless you are also booking a train on the same itinerary. This is due to a state law that was lobbied for by Greyhound, which didn't like the idea of a state-subsidized service competing with a privately-owned company. To get around this, you have three choices:
-Book the bus from BFD-LAX connecting to the Surfliner LAX-GDL, although the bus ride is 3 hours and the layover is 1 hour 45 minutes (time enough for a visit to Phillipe's and Olvera Street!) followed by a 13-minute train ride)
-Schedule your return to include a train trip
-Book (on a multi-city itinerary if necessary) a short trip by train that you don't plan on using and throw that ticket away (or save for a future exchange--this is called "throwaway ticketing" and is a commonly-exploited, if not completely ethical, loophole)--an example would be Wasco (WAC)-BFD-GDL or BFD-GDL-LAX. (Interestingly, booking WAC-GDL instead of BFD-GDL reduces the price from $25 to $15!).