No. A city's home rule authority is subject to the criminal laws of the state of Oregon. The Oregon Medical Marijuana Act (OMMA) and Measure 91 provide immunity from criminal prosecution for individuals who are acting within the parameters of those laws. Consequently, a council cannot remove the immunity provided by state law.
The immunity provided by state law does not extend to all crimes committed while engaging in marijuana-related activities. For example, the immunity provided by state law does not apply to the crime of driving under the influence. Likewise a city should be able to impose criminal penalties against a person engaging in a marijuana-related activity that violates another law, such as a business license ordinance, zoning or anti-smoking regulations. However, before doing so, the city should confirm that the state law immunities do not apply.