Are your photos being uploaded to iCloud?
On iPhone: Settings -> Apple ID -> iCloud -> Photos set to "on"
On MacBook: System Preferences -> Apple ID -> iCloud -> Photos checked
Sometimes, for some reason known only to Apple, my iPhone photos pause uploading to iCloud "to save battery." This happens even when the battery is fully charged. I have to go into the photo app, scroll to the bottom of the library tab, and tell it to resume. Once a photo gets to iCloud, it usually appears on my MacBook promptly.