I just got back 2 weeks ago and visited Versalles with Le Passport purchased from the Les Invalides train station. It included the train in both directions and, of course, includes both the Palace and the Gardens.
The Passport allows you to skip the "Purchase ticket" line but not the entry line, so you will still want to allow time for standing in line.
I went on Friday, August 15, paid for the "weekend pass" but discovered that the fountains were not turned on until 15:30 (3:30 pm). If you adjust your plans to go on a Friday, you should keep this in mind. I was making my way out of the Gardens at 15:30 when the fountains were turned on. I stuck around for a while to see a few of them, but did not retrace my steps to see them all. If you go on a Friday, go later in the day when the fountains will be on.