Hi,

You can submit both, under condition you only submit just one file format, or AI/EPS or jpg format.
If submitting the AI or EPS format the site makes the jpg available for download to.
Submitting both AI/EPS and jpg format is a waste of time for both you and reviewers.
When submitting the jpg format be sure not to use the vector word in title, description and keywords.

Conclusion : you're better of submiting the AI/EPS format because you can use the keyword vector (more visibiblity in search), and in the same time possible sale of a jpg format extracted from the vector.

Patrick.