You can insure your collection with your household insurance provider, but increasing the overall sum insured is not enough. What you need to do is inform your insurer about the purchase and have them explain what steps you need to take.
Typically, insurance providers use a whole set of insurance benefits for different types of items, so you will need to have them raise the coverage relevant to alcoholic beverages rather than just your total sum insured. Additionally, most insurers require you to list each item in your collection and its corresponding value. In some cases, photographs of each item are required.
You may be required to update the list as your collection grows and your bottles gain in value over time, and it is a good idea to do so in any case to avoid becoming under-insured.