Wirelessly posted (BlackBerry8530/5.0.0.601 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
The word "bump" has a very special meaning on FT. Are you talking about getting an "upgrade" to First Class? What's most important to you: upgrades? redeeming miles at a reasonable rate for award flights? free checked-baggage allowance? lounge access? Some programs are better at some things, but worse at others, so your priorities are important.
About how many miles a year do you fly?