In Cisco's terminology, trunking refers to the concept of links carrying multiple vlans across whereas channelling refers to bundling the links to behave as a single logical interface.
I am aware that other vendors out there sometimes call 'trunking' for what we call channelling and that MAY result in some confusion in the field.
So, in your case, you dont 'need' to configure port-channels on your two cat6k boxes but be aware that if you don't then spanning-tree would see them as individual links and block a port on one link to stop a loop in your L2 network. That is why, you may consider etherchannels also in your deployment.
In a nutshell, trunking can be turned ON by "switchport mode trunk" command under the interface and channelling can be turned on by issuing "channel=group mode desirable" under the physical interfaces where 'x' is the port-channel number. It is recommended for etherchannels that you first bundle the ports together by forming and etherchannel and THEN configure additional parameters like trunking etc.
here are the links:
Channelling:
CATOS:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_8_4/confg_gd/channel.htm
IOS:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/122sx/swcg/channel.htm
Trunking
CATOS:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_8_4/confg_gd/e_trunk.htm
IOS
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/122sx/swcg/layer2.htm
