If someone is addicted to opiates can they also be addicted to benzodiazepines?

Addiction. As dr. Ali says, the same person can be addicted to both substances if using both. Addiction is a pattern of using substances despite clear damage to relationships, work, life, etc -- and escalating this use also. The body becomes physiologically dependent on the substances & suffers withdrawal symptoms unless receiving them both. Mentally, the person desires the effects of the substances.
Opiates. Cross addiction to sedatives is very possible, due to reinforcing effects.
Not automaticlly. Opiates are different class of drugs.Addiction to opiates does not automatically make one addicted to benzodiazepines.