Bontrager used a few different hub designs on their branded wheels. The least expensive has has common loose ball (cup and cone) type bearings which will be adjustable and, BTW, benefit from annual regreasing. The more expensive wheels typically use cartridge bearings (often poorly termed "sealed bearings"). This type generally has more robust axles (less likely to be broken/bent) and the bearing maintenance is to replace the cartridge completely.

Both designs can have issues that result in a poor wheel spin. I do agree that the likely version you have is the least expensive cup and cone type. If so then you will need cone wrenches (likely 15mm) and a wrench that fits the lock nuts (usually 17mm). This type really wants the RH lock nut and cone to be well tightened against each other before doing the adjustments from the LH side. Sometmes this means removal of the cassette lock ring to access the RH lock nut and cone. This procedure then also requires a cassette lock ring removal tool and a chain whip to hold the cogs from spinning while the lock ring tool is turned. These tools will likely cost close to the service being done by a LBS. It's generally the second home servicing that tool costs are a savings compared to the shop doing the work. Good luck getting these tools in today's pandemic shortage of parts and tools available for sale.

BTW with either bearing design if the wheel has seen enough miles in the "bad" adjustment they are likely in currently, expect some bearing surface damage to be happening. All the more reason to plan on a complete servicing and not just a simple adjustment. Andy
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