Must match multiple values

If the document “must” be returned only if the id is 1 or 2, that sounds like another should clause. If I’m understanding your question properly, you want documents with either id 1 OR id 2. Additionally, if the color is yellow, give it a higher score.

Here’s one way you might achieve what you’re looking for:

{
  "query": {
    "bool": {
      "should": {
        "match": {
          "fruit.color": "yellow"
        }
      },
      "must": {
        "bool": {
          "should": [
            {
              "match": {
                "fruit.id": "1"
              }
            },
            {
              "match": {
                "fruit.id": "2"
              }
            }
          ]
        }
      }
    }
  }
}

Here I put the two match queries in the should clause of a separate bool query. This achieves the OR behavior you are looking for.

Have another look at the Bool Query documentation and take note of the nuances of should. It behaves differently by default depending on whether or not there is a sibling must clause and whether or not the bool query is being executed in filter context.

Another key option that is adjustable and can help you achieve your expected results is the minimum_should_match parameter. Have a look at this documentation page.