I just organised my own long term social visit visa, my partner is here on an employment pass. I came in on the free short-term social visit pass which is given on arrival and then arranged my LTSVP when I was here, it's quite quick.
It's a bit confusing because there are LTSVP from the immigration authority, as well as the ministry of manpower (who administers the employment pass)
If you're coming on an employment pass type 1 or 2, she can apply through the ministry of manpower which is much easier than the immigration department- however it means her pass is also sponsored by your employer, so they have to agree. If she has to apply through the immigration department she can apply longer than 6 months (I think) but will have to have a medical check.
Have a look at [url]htttp://
www.mom.gov.sg/publish/momportal/en/com ... visit.html[/url] for the details. You can apply for a longer term than 6 months, mine is the same length as my partners employment pass.
Oh, a tip for your partner- don't go to the ministry of manpower at lunchtime unless you take a good book to read, the wait times can be very long.