When you're done shooting a video, Vine asks if you want to share it and where. The workable options are either Twitter or just Vine. Facebook also is listed an option, but at launch time it wasn't working.
"Share on Vine" is checked by default, but you can uncheck it if you want your video to be private, and store it only in you Camera Roll. Even if you haven't previously granted Vine access to your Twitter account, you can check the Twitter button here on the sharing page and it will grab your Twitter account information for sending a tweet containing a link to your Vine video.
Click the green "DONE" button at the bottom of the screen when you're done.
Vine will show you an uploading bar while the upload is in progress. Sometimes it doesn't work and shows an "upload failed" message. Other times, the video will appear with a "waiting" message next to the video image. Try clicking the "uploading" button again if your video gets hung up on the "waiting" list.
Other Mobile Video Options
Instagram video is another popular option for shooting mobile video and sharing it through social networks. People think of Instagram as a photo sharing app, but it added a video recording feature in June 2013. The main differences with Vine are twofold: first, its videos can be about twice as long, up to 15 seconds. Second, it doesn't automatically loop its videos, they basically play once and users can opt to replay. See our illustrated guide to shooting Instagram videos for detailed instructions.