Called today because my account is coming up on a year old. CL was 10k asked for 15k. Spoke with very nice rep she went over my credit report and said had no problem bring it up to 15k.
Starting Score: 744
Congrats! 
Thanks. Now this is my highest credit line.
In the past year I have put about 22k on the card. I called the backdoor # and they pulled hard on TU.