Google tries to crawl and index everything including shortened URLs. Crawling & indexing is very different from ranking.
Is there a SEO benefit? I don't see a big benefit.
If you are having trouble getting indexed then building up backlinks & submitting a sitemap would probably be much more helpful for you.
If you are having trouble ranking, then focusing on powerful backlinks & the other 200 ranking signals would be better than using a URL shortener.
There is a small potential for SEO headaches with URL shorteners. If the shortened URL is using a 302 redirect or people start linking to the shortened URL instead of your real URL - you might have a problem.