While I agree that AMD doesn't do the best job explaining things, they are identical cores with the same HT. The key is the bandwidth provided by that bus. The Athlon 64 X2 has 8GBps available on the HT bus, and the Opteron 1xx chips have 8GBps available. Note that while it mentions the Opterons having up to 3 HT links, there is only one on the Opty 1xx.
You can compare the Architectural briefs to see that. Opteron:
http://www.amd.com/us-en/Processors/...6_8805,00.html
X2:
http://www.amd.com/us-en/Processors/...E13043,00.html
You can also see in this brief that AMD lists the HT frequency for the Athlon 64 X2 as 1000Mhz. Pg87:
http://www.amd.com/us-en/assets/cont...docs/30430.pdf