Do the AMD Phenom-II chips have the TLB/errata 298 problem?

Yes, they are free of this issue. TLB/errata 298 affected chips made in late 2007. The Phenom II X4 was released in February, 2009. The only chips which were affected were Phenom processors up to and including the "B2" and "BA" steppings. The chips released from March 27, 2008 and later are clear of the bug, as are all Phenom II processors. There's a bit more information in the Wikipedia article.