Welcome to the forums. Whether Amex pulls for new accounts can be wildly variable. For most of us that have existing personal accounts, Amex stopped pulling altogether for new personal accounts. My last HP from Amex was in 2002, but I opened two new cards with them last year. Amex does have some rules about how many revolving accounts can be applied for within certain timeframes, though. The title was a bit confusing; were you approved for Cash Magnet and are now looking to open an additional revolving personal account, or are you pre-approved for the card?
I app'd for 2 cards (1 revolver and 1 charge) within a day of each other and got 2 HPs, BUT I hadn't previously had an account with them, either business or personal, since 1999.
Cheers!
Recons on Amex starting lines are nearly unheard of. As long as you will not have received a CLI on any of your cards within the past 181 days by that point, once your card reaches 61 days, you can ask for a CLI to $3k, wait 181 days and ask for $9k, another 181 days and ask for $27k, etc. Sometimes they start out lines quite low, but as long as there is nothing in your profile that is scaring them away, they can grow QUICK. My wife took her ED card from $2k to $32k in 14 months.
Unless the rules have changed, you cannot be approved for more than 1 revolving credit card from Amex in any 5 day period, and no more than 2 cards (charge and/or revolving) in a 90 day period. It's possible you may be at or near your max with Amex for the moment. How long have you had the two business cards?