For Cruz, that's partly encouraging news. Name ID is a major hurdle for many pols with potential designs on higher office. (Cruz is frequently mentioned as a potential presidential candidate and has not ruled out a run.) And the bump up cost him nothing dollar-wise -- it came after earned media from his push to shred Obamacare and his marathon filibuster, among other things.
The bad news for Cruz is that the more people have gotten to know him, they less they like him. He went from having a 6-point net positive favorable rating to a 10-point net negative rating.
It's important to keep in mind that the poll is of all adults. Cruz has been courting a specific subset of that group with his Obamacare fight and cast-iron conservative posture on various other issues: conservative Republicans.
Cruz is a hero to the conservative base right now. For the moment, the only thing that matters for his political stock is how he is viewed by that cross-section of Americans. That's where he draws his strength.
Of course, if Cruz does run for president and if he wins the GOP nomination -- two very big ifs -- then the way he is viewed more broadly will matter much more. And early indications are that it would be a problem for him.