Engrav,
You definitely need more bids but you also need to do some homework first. You should decide what the scope of work is for the contractors. Based on the two bids it looks to me that you're letting the contractors decide this. If you don't know what is needed you can determine this two ways. First, hire an expert as a consultant to thoroughly inspect the pool for what is required then combine that with your preferences for materials, features etc. Or you can invite contractors to inspect your pool and make recommendations in two areas. First, any defects that NEED to be repaired and second, recommendations they may make to improve the function and appearance. After a few of these meetings you'll start to see a pattern and that should help you settle on a scope. Along the way you'll also be "pre-qualifying" the contractors. Have a list of questions like:
How long have you been in business?
Have you done any pools in my area?
Are there any aspects of this work that you've not done before?
How long have your crews been working for you?
What is the most difficult part of this job?
You'll get answers and importantly you'll decide if your personality is compatible with the builder which is very important. After doing this you'll be ready to get quotes. The contractors may give you some pricing as you conduct these inspections and that's helpful but not a competitive pricing process. There are lots of superb contractors that really know their reputation is all they have and they are truly trustworthy. Problem is there are also the opposite out there and you can't tell which is which. References help but in my experience there are many contradictions even with this.
After you have a written scope of work pick the top 3 bidders. Then send them an invitation to bid and tell them only 3 bidders are bidding. This does a couple of things for you. First it lets them know they're competing so they need to sharpen their pencil, also they know they're not "bidding against the entire world" so they have a reasonable chance to get the work. They'll work harder to get this job because they've got a better chance. And lastly, you'll be seen as a high quality owner that may not be a pool expert but he definitely has his act together. Most good contractors like good owners.
If you have a good scope you'll have bids that are easily comparable. Make a list of work items and make sure the bidders fill out each line's price. If they won't provide enough detail for you to analyze the work disqualify them and get another bid. Also for areas where the scope cannot be defined (such as loose tiles) have each estimate the area needing repair and price any extra repair as a unit price. Then you can normalize the price base on the average of the bidders and their unit prices. Lastly, watch out for vague, one-way terms or conditions in their price. Items like "minor surface cracks and hazing". What in the world does that mean and who decides what minor is? If all bidders use this term you should at least get some definition of "minor" in clear measurable terms like 1/32" and smaller or 3/8" deep or something like that.
I hope this helps and please feel free to ask me any follow-up questions.
Chris