Most aftermarket bumpers are not load rated. Not because they cant handle the load, but because it costs a lot of money to have it certified with the national highway safety admin. I have a pos rugged ridge china made bumper on my tj and I am more concerned with my frame breaking then the bumper.
I pull my water logged 20' hurricane deck boat all over with my tj and have had no problems with the rr bumper.Im sure it is over 3500 lb.
Just make sure to buy frame tie ins if the bumper does not come with them. Most dont.