Are your other credit cards personal cards or Business cards? Most Business cards are not reported to personal credit bureaus, and Chase would not know that they exist. If they are personal cards, have you obtained a copy of your credit reports to verify that these accounts are reported accurately? You can obtain free copies of your reports here:

https://www.annualcreditreport.com/index.action

If both accounts are reported accurately, it is possible that Chase's algorithm does regard two accounts as "too few", and you will need to call the reconsideration line to explain. Bear in mind that your application was not examined or denied by a person, it's all automated.

Having deposit accounts with Chase is not a requirement to open a card, BUT it may help if you have a "thin" credit file.