Just want to confirm that if I have a premium account of Salesforce; do they provide support for mobile SDKs. The SDKs are opensource available at github; please confirm if Salesforce Support will help in case of any issue in SDK.
Yes, Salesforce does support Mobile SDK as part of premium support.
However, you actually don't need premium support for mobile, if you are facing an issue with Mobile SDK, you can either post on the Salesforce Mobile SDK Google+ community. The questions on the G+ community are answered directly by the Mobile SDK team as well as the community(such as yours truly)