Yes, this is right. The delegates in Texas are apportioned along state-senate-district lines, with districts that voted in higher numbers for Democrats in the previous gubernatorial and presidential elections getting more delegates. So the district that encompasses most of Austin gets 8, the "black districts," one in Houston and the one in Dallas, get 7, the Latino districts in San Antonio and the Valley get 4, 5, or 6, etc. In some ways, Clinton seems to be getting screwed by historical circumstances: in 2004, Latinos voted for Bush in higher percentages than they usually vote for Republicans--though the counties in the Valley still were the only ones in Texas, besides Austin's county, that Kerry took--and the 2006 Democratic guv candidate was extremely uninspiring and that race was split by two independent candidates, meaning the Latino districts that are Clinton's base of support had fewer delegates than they might have, say, eight years ago or four years from now.
As it stands, the last I heard, because she was only four delegates ahead after the primary vote, Obama's showing in the caucuses means he will probably end up with between one and four more delegates overall. Best case for Hillary seems to be a tie or one ahead.
Oh, and "hotbed" is an understatement for Obama's support here. It's really awful.