Which Chase are you applying for? A year go they didn't have the 5/24 policy which is aimed at AORer and other churners, now (since May 2015) they do for all personal non-partner cards, business cards expected to do same next month, and personal cards expected to that the month after that.
Meanwhile, why in the world do you want to a credit line increase before applying for a new Citi card??? Most people want to a credit line decrease to make it more likely that Citi will give them sufficient credit on the new card.

But decreasing credit requires at least a few weeks of wait before it's available for a new card.

And cancelling requires months of wait before the credit is free'd up and available for a new card.

So definitely don't cancel, and you may or may not want to reduce credit (but definitely don't increase credit) before applying for the new card, depending on how soon you'll apply for the new card.


Finally, do you realize that apporamas are pretty dead (have outlived their usefulness)? They were created back in the days when it would take a day or so for inquiries from your first card application to be visible to another bank. Now it's visible "instantaneously", so there's usually no big benefit any more to applying for cards from different banks on the same day. With Chase's 5/24 policy counting new cards open on your credit report (not inquiries/pulls), there's a benefit to applying for Chase first (since while pulls/inquiries are "instantaneous", it takes longer for new card accounts to actually show up on credit report, but since Chase can easily take many weeks before they approve you (and you generally don't want to call), you may not want to apply for another bank's card until your Chase app is approved, so just submitted!