Yes, Tammy's partner is her brother Victor. I just registered to post that, but since you guys beat me to the punch...
I'll help you out with a few more, since the cast will be announced on Mon anyways:
Amanda Blackledge is racing with her boyfriend, KRISTOPHER (Kris) KLICKA:
He's 25, from San Diego. A recent college graduate.
Jodi Wincheski's partner is a flight attendant named CHRISTI (not Chrissy). This is her:
So, the "confirmed" cast, just to summarize, is now as follows:
Luke Adams. 22. Student . Colorado Springs, Colorado. Mother / Son
Amanda Blackledge. 23. Student. San Marcos, California. Dating
Kris Klicka. 25. College Grad. San Diego, California. Dating
Tamara "Tammy" Jih. 27. Attorney. San Francisco, California. Brother / Sister
Jennifer Hopka. 26. Nurse / Model. Columbia, South Carolina. Dating
Preston McCamy. 28. Model / Actor. Columbia, South Carolina. Dating
Victor Jih. 35. Attorney. Los Angeles, California. Brother / Sister
Mark Munoz. 35. Stunt Actor. Los Angeles, California. Brothers
Mike White. 38. Writer / Actor. Los Angeles, California. Father / Son
Michael Munoz. 40. Stunt Actor. Los Angeles, California. Brothers
Jodi Wincheski. 40. Flight Attendant. Houston, Texas. Co-workers
Victoria Pfeifer Hunt. 47. Tax Accessor. Columbus, Ohio. Married
Margaret Adams. 49. Colorado Springs, Colorado. Mother / Son
Brad Hunt. 51. Electric Company. Columbus, Ohio. Married
Mel White. 68. Reverend. Lynchburg, Virginia. Father / Son
RFF always does such a good job with the Amazing Race. Keep up the good work!