The most common repairs that you will come across for your bubble tent is broken, or bent poles. This is quite easily remedied as all the main tent manufacturers have replacement poles for order. So it is just a case of purchasing a replacement part. So I would deem this as minor.
Almost as common is a split seam in your tents lining or a guy wire anchor giving way. I am sure all you campers have been there – tripping over a guy line at night or having to much pressure on the seams of your bubble tent. It is imperative that you purchase and have with you a small sowing kit when you go camping, often when you buy your tent they can come included. This will enable you to deal with simple repairs of this type. You need to use small and even spaced stitches when repairing your tent, try and resist the temptation to rush the repair with fewer and bigger stitches. If you take you time with the repair, you can be assured that you will have done a tough job that will last a long time.
Most suppliers of bubble tents have tape-sealed seams. They can leak but you can easily repair them with proprietary seam sealer, again lots of tents come supplied with a small tube for your use. Do not try and seal seams if the tent is wet you need to wait until it is thoroughly dry. Paint the sealer on the seam and let dry for a day or two if possible. Best to do it at the start of your camping trip. The sealer is very sticky and can stick to other parts of the tent so be extra careful to make sure that it does not come into contact with a zip.
Any tears and punctures in the bubble tent fabric and groundsheet can be fixed temporarily with gaffer tape which is also suitable for a temporary repair on tent poles if you have no spares on your camping trip. Always make sure you have a roll in the car with you. Good quality tents often have self-adhesive patches for a more permanent fix.
The main point to make is that with any bubble tent repair makes sure that the area around the repair is sufficiently clean and dry, then get someone to hold a flat object like a CD case behind the hole, so you have something firm to push against, this enables you to repair the damage without any creases or bubbling.