Yes, two devices from different companies can communicate with each other, and possible bridge. The standards are standard, and it doesn't matter who makes the device.
For the next point, since you upgraded to Wireless N on only one of your devices (the TrendNet TEW-369GR seems to be the only one that can go to N) that is the one that should be the central connection point for your home network. Any devices that can bridge to it will be up to the capability of THAT device, not the TrendNet device.
So, as for your other device, the TP-link TL-WR541G, that device can only go as far up the wireless chain as a G device. But can it bridge?
From what I read at the http://www.tp-link.com/ website, YES it can. So, just get the User Manual for the device and version of that device that you have and follow the instructions for getting it to bridge.
I just recently upgraded to a Wireless N Gigabit Router from a Wireless G Router. I would like to know if I can bridge the following routers so I can increase the range of the wireless signal in my home. The two routers I have are the TRENDnet TEW-369GR and the TP-LINK TL-WR541G. But I don?t know the way to bridge the two routers together and I don?t even know if they can be bridged since there from two different companies. Can anyone help me setup the two routers so they can be bridge, if possible? Thanks for any help that you may provide.