I am not sure if any of them can be called a proper all-rounder.
They are listed as "All-rounder", because Moeen makes the team as a combination of 5th bowler & 6th batsman, while Jaddu is probably a bit better in that regard, because in IND at least, he makes the team as 4th bowler & definitely not a Tail-ender. I am not sure if Moeen would have ever made the ENG team only as a batsman (may be now, as he is in great form, but players with similar stats will never make ENG team as specialist batsman), but Jaddu probably still makes the team as a spinner in IND.
As all-rounder, over-all I'll go for Moeen, but in their best & on favorable condition, Jaddu is the better match winner in Test. In ODI, Jaddu was far better till last year, but since then he has declined big time - not sure, if he makes the ODI team ahead of Axer/Mishra now as his bowling has declined & batting hardly exists now days. On contrary, Moeen is becoming a very useful ODI all-rounder, who bowls 10 overs & can bat across the batting order. Both of them are very good fielders, but Jad is among the best in world as an all-round fielder.
I think, Jaddu is fading away fast while Moeen is getting stronger by every series - I won't be surprised, if Jaddu loses his Test spot after home series, but Moeen will be almost certainly there for best part of a decade going forward for ENG set-up in all 3 formats. He is almost there to make the ENG Test team simply as batsman.