Originally Posted by ashill

Yes, because your ticketed allowance will be two bags.

There are two factors in bag fees.

1) Your ticketed allowance. This will be printed on the ticket (by Federal law in the US) and will apply to all portions of a single ticket (also Federal law), regardless of which airline you check in with.

2) Any status- or credit card-based waivers of the ticketed allowance. This is dependent entirely on the operating carrier of the first segment (i.e. the airline you check in with) and therefore might be different for different legs on the same ticket. In some cases (eg DL/SkyTeam, AA/oneworld, UA/Star, or AA/AS) there are negotiated reciprocal agreements where status on one airline gets a bag fee waiver on flights operated by another, but what typically matters is the existence of a waiver for the airline you check in with. I don't know of any cases in which credit card bag fee waivers apply on partners.

The distinction between 1 and 2 is often confusing and is the genesis of this thread. It's also a distinction that DL's web site makes insufficiently clear.