I've had the Cash Rewards card since July 2016--started at $5k and within 3 years took it the the current $40k with HP and SP CLIs. Plus I just moved a fairly good size chunk of money into new savings and checking accts. with them and already have Gold Preffered status. Currently have a $4.5k balance on the card. Also have a 0% BT offer which I plan to take advantage of moving a majority of my Lowe's balance over to it in about 10 days after the statement cuts.
The BT+ my existing balance will put me at almost 20% UTL on the card--so I thought I'd shrink that a little by asking for a CLI. Haven't asked for one in 3 years b/c I've been happy with the current limit. Asked to take it to $50k--7 to 10 day message. This morning received the email: DECLINED--letter on the way. No counter offer either. If I had to guess I'd say it's because I'm currently carrying at least $4k balances or a little more on about 4 high limit cards--including B of A--plus a few lesser amounts on other cards. B of A has me at 755 on TU at the momeent. 8% UTL total across all accounts. Roughly $95k income not counting assets. Was a little thrown off b/c of the fact I have a good chunk of money parked with them at the moment--but not too suprised or upset neither b/c my first thought after the decline was the high balances--plus B of A granted me that $40k line at a time in my rebuild where I was darn lucky to get it. I currently have the offer for the $1.5% CU card--but I'm glad I didn't waste the HP b/c I'm sure if they had approved it--they would have just taken from my CR to open the account. Still going to do the BT anyway. Just posted this as a data point to show even if you have Preferred status--it doesn't necessarily --make you a shoe-in for new cards or CLIs.
BUSINESS 
While Preferred (or any other) status can be a plus to a BoA/ML relationship, your DPs definitely confirms it will not always translate into successful CLIs and/or new CC approvals. There can be exceptions of course 
On the upside, you're not upset about the decision since you are still doing the BT.
I'd be curious about any additional DPs you can share when you receive the letter.
@FinStar: Naw--I can't be too upset with them--after all they gave me my first "mega" limit. I'm kinda glad it worked out this way b/c if I did app for the 1.5% Cash card (I currently have the offer for it) or the Premium Rewards--I def. didn't want to burn a HP just to be declined or have them pull part of the limit from my Cash Rewards to get an approval. This was only a SP so it worked out okay. Would have been sweet to finally have my first $50k card though. I'll try again later in the year when and if I get my balances back down to 5% total UTL or below.
@Credit-hoarder wrote:
Roughly $95k income not counting assets.
This, alone, may cap you from further CLI eligibility on this card. In my experience, BA limits total credit line exposure to approx 50% of your stated income.
@hdporter wrote:
@Credit-hoarder wrote:
Roughly $95k income not counting assets.This, alone, may cap you from further CLI eligibility on this card. In my experience, BA limits total credit line exposure to approx 50% of your stated income.
I've heard about the 50% of income cap also. But 50% of $95K is $47.5k. My current line is $40k---still some room to grow the card.
@Credit-hoarder wrote:I've heard about the 50% of income cap also. But 50% of $95K is $47.5k. My current line is $40k---still some room to grow the card.
I characterized that cap as "approx" because I haven't seen info sufficient to nail it at exactly 50%.
Plus, when I look back at my and DW's BA CLI's over the past 5 years, they range from 25% to 60%. You're suggesting you're eligible for 19%, at most. My data is a very small dataset to work from, but it may be that they don't do/approve anything less than 20%. < just sayin' >