Will insurance-provided wellness programs still exist under obamacare?

Yes. The type of plan and level coverage that an insurance company sells through the Obamacare health insurance marketplaces should be the same quality plan as the company sells to people outside of the marketplace program. California's marketplace will sell several levels of coverage. Preventive care services (wellness programs) are in the plans offered to people inside and outside the marketplaces.
Yes. Yes, these programs save the insurance companies money and increase their profits by way of decreased health care needs of the participants. Therefore, you can be sure that they will continue to exist!