Need help traveling outbound on CO with a return on DL
 

Do I need to call? I'm not finding any way to come up with the following itinerary online: EWR-TLV outbound (CO) and return TLV-ATL-PBI (DL) with both dates of travel happening during the second and third weeks of January.

It seems that CO's reward travel search does not include flights on DL metal and I'm finding the same problem, but vice versa, on DL's site.

I think you've answered your own questions, if you can't find what you want online, you should call.

Revenue or reward?

CO will issue either one if you call them. I'm sure that DL will issue the reward one, but I haven't tried to use them to issue a revenue ticket on multiple carriers.