Hi Ralph
Is this your first time researching on the Oz boards - or have you been researching previously in Australia? Your post caught my eye because my gg grandmother was a
Mary (just checked - she was Sarah

) Ann Chambers (but her married name) who came from Maidstone Kent. They didn't arrive in Australia until 1873, so probably no relationship to be easily found.
The immigration records in Australia are by state until the 1920s. As your couple married in Victoria, it is a good chance they arrived in that state, but not guaranteed.
The link given by terra gives both assisted and unassisted immigrant lists into Victoria, as well as passengers leaving Victorla (doesn't seem to be an Edward lancaster leaving - but lots of Mr & Mrs)
Do you have the marriage certificate for your couple. Their ages could be useful in finding the correct immigration record. There is a Mary Ann Chambers arriving in 1856 aged 25 - possible
There is additional information from the indexes available at prov and some libraries within Australia - if you find any likely folks, you could ask for a lookup - and may find someone who can check. There is always more information available about assisted passengers - If you paid your own fare - no-one much cared!
hope this helps
Trish